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- 1. Appl. Phys. Lett. 90, 021920 (2007) , “Hydrogen passivation of nitrogen in GaNAs and GaNP alloys: How many H atoms are required for each N atom?”, I. A. Buyanova, W. M. Chen, M. Izadifard, S. J. Pearton, C. Bihler, M. S. Brandt, Y. G. Hong, and C. W. TuSecondary ion mass spectrometry and photoluminescence are employed to evaluate the origin and efficiency of hydrogen passivation of nitrogen in GaNAs and GaNP. The hydrogen profiles are found to closely follow the N distributions, providing unambiguous evidence for their preferential binding as the... (Read more)
- 2. Phys. Rev. B 75, 195335 (2007) , “Computational and experimental imaging of Mn defects on GaAs (110) cross-sectional surfaces”, A. Stroppa, X. Duan, M. Peressi, D. Furlanetto, and S. ModestiWe present a combined experimental and computational study of the (110) cross-sectional surface of Mn δ-doped GaAs samples. We focus our study on three different selected Mn defect configurations not previously studied in detail, namely surface interstitial Mn, isolated and in pairs, and... (Read more)
- 3. Phys. Rev. B 75, 195207 (2007) , “Effects of optical absorption on 71Ga optically polarized NMR in semi-insulating GaAs: Measurements and simulations”, Stacy Mui, Kannan Ramaswamy, and Sophia E. HayesThe intensity and the hyperfine shift of optically polarized NMR (OPNMR) signals of 71Ga in semi-insulating GaAs have been found to depend on the photon energy and the helicity of light used for optical pumping. Single-crystal GaAs wafers of two different thicknesses, 400 and 175 ... (Read more)
- 4. Phys. Rev. B 75, 115205 (2007) , “Stability of I3 complexes in III-V compound semiconductors by tight-binding molecular dynamics”, G. Zollo and F. GalaIntrinsic interstitials in GaAs are known to have a large formation energy that makes their concentration almost negligible in as-grown materials. However, interstitials must be explicitly considered in implanted GaAs where collision cascades, induced by the energetic ions, produce a large amount of... (Read more)
- 5. Phys. Rev. B 75, 113310 (2007) , “Hole spin polarization in GaAs:Mn/AlAs multiple quantum wells”, V. F. Sapega, O. Brandt, M. Ramsteiner, K. H. Ploog, I. E. Panaiotti, and N. S. AverkievWe study the effect of confinement on the spin polarization of holes bound to Mn acceptors in paramagnetic GaAs:Mn/AlAs multiple quantum wells. It is demonstrated that the polarization of these bound holes is governed by the properties of the host material rather than by quantum confinement. The... (Read more)
- 6. Phys. Rev. Lett. 98, 206403 (2007) , “H-Induced Dangling Bonds in H–Isoelectronic-Impurity Complexes Formed in GaAs1-yNy Alloys”, A. Amore Bonapasta, F. Filippone, and G. MattioliComplexes formed by H and the isoelectronic impurity N in GaAs1-yNy alloys have been widely investigated because the significant effects of N on the GaAs properties and their passivation by H represent a unique tool for a defect engineering of semiconductors.... (Read more)
- 7. Phys. Rev. Lett. 98, 077601 (2007) , “Multiple-Pulse Coherence Enhancement of Solid State Spin Qubits”, W. M. Witzel and S. Das SarmaWe describe how the spin coherence time of a localized electron spin in solids, i.e., a solid state spin qubit, can be prolonged by applying designed electron spin resonance pulse sequences. In particular, the spin echo decay due to the spectral diffusion of the electron spin resonance frequency... (Read more)
- 8. Phys. Rev. Lett. 98, 026802 (2007) , “Microscopic Basis for the Mechanism of Carrier Dynamics in an Operating p-n Junction Examined by Using Light-Modulated Scanning Tunneling Spectroscopy”, Shoji Yoshida, Yuya Kanitani, Ryuji Oshima, Yoshitaka Okada, Osamu Takeuchi, and Hidemi ShigekawaThe doping characteristics and carrier transport in a GaAs p-n junction were visualized with a ~10 nm spatial resolution, using light-modulated scanning tunneling spectroscopy. The dynamics of minority carriers under operating conditions, such as recombination, diffusion, and electric... (Read more)
- 9. Physica B 401, 250 (2007) , Elsevier , “Doubly charged state of EL2 defect in MOCVD-grown GaAs ”, Nazir A. Naz, Umar S. Qurashi, Abdul Majid and M. Zafar IqbalEL2 is the ubiquitous native defect in crystalline GaAs grown by a variety of different techniques. It has been proposed to be a doubly charged deep-level center with two states having distinct energy levels in the band gap. While the singly charged state has been the subject of many experimental studies and is, therefore, well established, the doubly charged state has only been occasionally alluded to in the literature. This paper provides evidence for a dominant inadvertent deep level in p-type GaAs most likely to be the doubly charged state of the EL2 center. Deep-level transient spectroscopy (DLTS) has been applied to characterize epitaxial layers of p-type GaAs grown on p+ GaAs substrates by low-pressure metal organic chemical vapor deposition (LP-MOCVD). A pronounced peak is observed in the majority carrier (hole) emission deep-level spectra. Thermal emission rate of holes from the corresponding deep level is found to exhibit a strong electric field dependence, showing an increase of more than two orders of magnitude with an increase of the electric field by a factor of~2. The thermal activation energy for this level is found to vary from 0.29 to 0.61 eV as the electric field is varied from 2.8×105 to 1.4×105 V/cm. Direct pulse-filling measurements point to a temperature-dependent behavior of the hole capture cross section of this level. We identify this inadvertent deep-level defect, commonly observed in p-type AsGa grown by a variety of different methods, with the doubly charged state of the well-known AsGa antisite related defect, EL2. (Read more)
- 10. Advances in Science and Technology 46, 73 (2006) , Trans Tech Publications, Switzerland , “Electric-Field-Enhanced Thermal Emission from Osmium-Related”, M. Zafar Iqbal, A. Majid, A. Dadgar and D. BimbergDeep-level defects related with 5d transition metal, osmium (Os) have been studied in ntype GaAs. Os has been incorporated in epitaxial n-GaAs layers in situ, during growth by lowpressure metal-organic chemical vapour phase epitaxy (MOVPE) technique. Mesa p+nn+ junction diodes are fabricated for investigations by deep level transient spectroscopy (DLTS). Two deeplevel peaks, observed in majority carrier (electron) emission spectra, Os1 and Os2, show a significant shift in peak positions to lower temperatures with the applied junction reverse bias, demonstrating enhancement of the thermal emission rate by the junction electric field. Doublecorrelation DLTS (DDLTS) measurements have been employed for accurate quantitative investigations of the observed field dependence. However, in view of the relatively small concentration of the deep level Os1, this technique is found to yield reliable data only for the deep level corresponding to the dominant peak, Os2. Detailed data have been obtained on the field effect for Os2, extending over junction electric field values 3 x 106 V/m - 1.2 x 107 V/m. The measured emission rate signatures show a reduction of the thermal activation energy from 0.48 eV to 0.21 eV for Os2 over this electric field range. Analysis of the data in terms of the recent theoretical work on field dependence indicates that Os2 is associated with a substitutional Os donor. (Read more)
- 11. Appl. Phys. Lett. 89, 231901 (2006) , “Cathodoluminescence investigations of GaInNAs on GaAs(111)B”, J. Miguel-Sánchez, U. Jahn, A. Guzmán, and E. MuñozIn this work, we present a detailed cathodoluminescence characterization of GaInNAs quantum wells grown on GaAs(111)B. As-grown and annealed InGaAs and GaInNAs quantum wells were maeasured and compared by spatially resolved cathodoluminescence at different photon energies. In the case of... (Read more)
- 12. Appl. Phys. Lett. 89, 152910 (2006) , “Characterization of atomic-layer-deposited Al2O3/GaAs interface improved by NH3 plasma pretreatment”, Hong-Liang Lu, Liang Sun, Shi-Jin Ding, Min Xu, David Wei Zhang, and Li-Kang WangAl2O3 thin films were deposited by atomic layer deposition on HF-cleaned and NH3 plasma-treated GaAs surfaces, respectively. The precursors used for Al2O3 films are trimethylaluminum and water. Effects of NH3 plasma pretreatment on... (Read more)
- 13. Appl. Phys. Lett. 89, 092103 (2006) , “Electron energy barriers at interfaces of GaAs(100) with LaAlO3 and Gd2O3”, V. V. Afanas'ev, A. Stesmans, R. Droopad, M.Passlack, L.F. Edge, D. G. SchlomElectron energy barriers at the interfaces of GaAs(100) with Gd2O3 appear to be insensitive to the Fermi level pinning indicating that charges at interface states are of marginal importance for the band alignment at semiconductor/insulator interfaces. The inferred conduction... (Read more)
- 14. Appl. Phys. Lett. 89, 061903 (2006) , “Nitrogen related vacancies in GaAs based quantum well superlattices”, J. Slotte, K. Saarinen, E.-M. Pavelescu, T. Hakkarainen, and M. PessaThe authors report on the influence of nitrogen incorporation on vacancies in GaAs based superlattices. The samples were molecular beam epitaxy grown on p-type GaAs substrates with the superlattice structure consisting of ten periods of quantum well material separated by GaAs buffers. Three... (Read more)
- 15. Appl. Phys. Lett. 89, 012505 (2006) , “Diffusion and clustering of substitutional Mn in (Ga,Mn)As”, Hannes Raebiger, Maria Ganchenkova, and Juhani von BoehmThe Ga vacancy mediated microstructure evolution of (Ga,Mn)As during growth and postgrowth annealing is studied using a multiscale approach. The migration barriers for the Ga vacancies and substitutional Mn together with their interactions are calculated using first principles, and temporal... (Read more)
- 16. J. Appl. Phys. 100, 083521 (2006) , “Thermally activated charge reversibility of gallium vacancies in GaAs”, Fedwa El-Mellouhi, Norm, and MousseauThe dominant charge state for the Ga vacancy in GaAs has been the subject of a long debate, with experiments suggesting −1, −2, or −3 as the best answer. We revisit this problem using ab initio calculations to compute the effects of temperature on the Gibbs free energy of... (Read more)
- 17. J. Appl. Phys. 100, 064910 (2006) , “Defects in Ga(In)NAs thin films grown by atomic H-assisted molecular beam epitaxy”, Yukiko Shimizu, Yusuke Mura, Akira Uedono, and Yoshitaka OkadaThe vacancy-type defects in Ga1–yInyNxAs1–x dilute nitride films grown by atomic H-assisted molecular beam epitaxy (H-MBE) were investigated. The positron annihilation measurements showed that the densities of... (Read more)
- 18. J. Appl. Phys. 100, 053516 (2006) , “Damage production in GaAs and GaAsN induced by light and heavy ions”, C. Björkas, K. Nordlund, K. Arstila, J. Keinonen, V. D. S. Dhaka, and M. PessaIon irradiation causes damage in semiconductor crystal structures and affects charge carrier dynamics. We have studied the damage production by high-energy (100 keV–10 MeV) H, He, Ne, and Ni ions in GaAs and GaAs90N10 using molecular dynamics computer simulations. We... (Read more)
- 19. J. Appl. Phys. 100, 044503 (2006) , “Dislocation dynamics in strain relaxation in GaAsSb/GaAs heteroepitaxy”, B. Pérez Rodríguez and J. Mirecki MillunchickThe real-time stress evolution has been investigated during molecular-beam epitaxial growth of GaAs1–xSbx/GaAs metamorphic buffer. These real-time data were obtained using an in situ multibeam optical sensor measurement and has been combined with... (Read more)
- 20. J. Appl. Phys. 100, 034503 (2006) , “Deep level defects in proton radiated GaAs grown on metamorphic SiGe/Si substrates”, M. González, C. L. Andre, R. J. Walters, S. R. Messenger, J. H. Warner, J. R. Lorentzen, A. J. Pitera, E. A. Fitzgerald, and S. A. RingelThe effect of 2 MeV proton radiation on the introduction of deep levels in GaAs grown on compositionally graded SiGe/Si substrates was investigated using deep level transient spectroscopy (DLTS). Systematic comparisons were made with identical layers grown on both GaAs and Ge substrates to directly... (Read more)
- 21. Nature 442, 436 (2006) , “Atom-by-atom substitution of Mn in GaAs and visualization of their hole-mediated interactions”, D. Kitchen, A. Richardella, J. -M. Tang, M. E. Flatt, A. YazdaniThe discovery of ferromagnetism in Mn-doped GaAs1 has ignited interest in the development of semiconductor technologies based on electron spin and has led to several proof-of-concept spintronic devices2, 3, 4. A major hurdle for realistic applications of Ga1-XMnXAs, or other dilute magnetic semiconductors, remains that their ferromagnetic transition temperature is below room temperature. Enhancing ferromagnetism in semiconductors requires us to understand the mechanisms for interaction between magnetic dopants, such as Mn, and identify the circumstances in which ferromagnetic interactions are maximized5. Here we describe an atom-by-atom substitution technique using a scanning tunnelling microscope (STM) and apply it to perform a controlled study at the atomic scale of the interactions between isolated Mn acceptors, which are mediated by holes in GaAs. High-resolution STM measurements are used to visualize the GaAs electronic states that participate in the Mn–Mn interaction and to quantify the interaction strengths as a function of relative position and orientation. Our experimental findings, which can be explained using tight-binding model calculations, reveal a strong dependence of ferromagnetic interaction on crystallographic orientation. This anisotropic interaction can potentially be exploited by growing oriented Ga1-XMnXAs structures to enhance the ferromagnetic transition temperature beyond that achieved in randomly doped samples. (Read more)
- 22. Phys. Rev. B 74, 245205 (2006) , “Mn incorporation in as-grown and annealed (Ga,Mn)As layers studied by x-ray diffraction and standing-wave fluorescence”, V. Holý, Z. Matj, O. Pacherová, V. Novák, M. Cukr, K. Olejník, and T. JungwirthA combination of high-resolution x-ray diffraction and a technique of x-ray standing-wave fluorescence at grazing incidence is employed to study the structure of a (Ga,Mn)As-diluted magnetic semiconductor and its changes during post-growth annealing steps. We find that the film is formed by a... (Read more)
- 23. Phys. Rev. B 74, 241303(R) (2006) , “Enhancement of interactions between magnetic ions in semiconductors due to declustering”, A. Franceschetti, S. V. Barabash, J. Osorio-Guillen, A. Zunger, and M. van SchilfgaardeIt is often assumed that the exchange interaction between two magnetic ions in a semiconductor host depends only on the distance and orientation of the magnetic ions. Using first-principles electronic structure calculations of Mn impurities in GaAs, we show that the exchange interaction between two... (Read more)
- 24. Phys. Rev. B 74, 235213 (2006) , “Mn 3d electronic configurations in (Ga1−xMnx)As ferromagnetic semiconductors and their influence on magnetic ordering”, F. Kronast, R. Ovsyannikov, A. Vollmer, H. A. Dürr, W. Eberhardt, P. Imperia, D. Schmitz, G. M. Schott, C. Ruester, C. Gould, G. Schmidt, K. Brunner, M. Sawicki, and L. W. MolenkampWe applied x-ray absorption spectroscopy and x-ray magnetic circular dichroism (XMCD) at the Mn 2p-3d resonances to study the Mn 3d electronic configuration and the coupling of Mn 3d magnetic moments in various Ga1−xMnxAs films.... (Read more)
- 25. Phys. Rev. B 74, 205207 (2006) , “Charge-dependent migration pathways for the Ga vacancy in GaAs”, Fedwa El-Mellouhi, Norm, and MousseauUsing a combination of the local-basis ab initio program SIESTA and the activation-relaxation technique we study the diffusion mechanisms of the gallium vacancy in GaAs. Vacancies are found to diffuse to the second neighbor using two different mechanisms, as well as to the first and fourth... (Read more)
- 26. Phys. Rev. B 74, 165204 (2006) , “Electronic structure of rare-earth impurities in GaAs and GaN”, A. Svane, N. E. Christensen, L. Petit, Z. Szotek, and W. M. TemmermanThe electronic structures of substitutional rare-earth (RE) impurities in GaAs and cubic GaN are calculated. The total energy is evaluated with the self-interaction corrected local spin density approximation, by which several configurations of the open 4f shell of the rare-earth ion are... (Read more)
- 27. Phys. Rev. B 74, 161201 (2006) , “Detection of magnetic resonance of donor-bound electrons in GaAs by Kerr rotation”, T. A. Kennedy, J. Whitaker, A. Shabaev, A. S. Bracker, and D. GammonMagnetic resonance of electrons in lightly doped GaAs layers has been detected at 5.8 T by magneto-optical Kerr rotation. A study over a wide range of microwave powers shows (1) resonance without dynamic nuclear polarization (DNP), (2) resonance enhanced by DNP, and (3) DNP pinning of the resonance... (Read more)
- 28. Phys. Rev. B 74, 155203 (2006) , “Antisite effect on hole-mediated ferromagnetism in (Ga,Mn)As”, R. C. Myers, B. L. Sheu, A. W. Jackson, A. C. Gossard, P. Schiffer, N. Samarth, and D. D. AwschalomWe study the Curie temperature and hole density of (Ga,Mn)As while systematically varying the As-antisite density. Hole compensation by As-antisites limits the Curie temperature and can completely quench long-range ferromagnetic order in the low doping regime of 1%–2% Mn. Samples are grown by... (Read more)
- 29. Phys. Rev. B 74, 153201 (2006) , “Light-induced hyperfine 69Ga shifts in semi-insulating GaAs observed by optically polarized NMR”, Kannan Ramaswamy, Stacy Mui, and Sophia E. HayesWe report the observation of 69Ga NMR light induced hyperfine shifts at 6 K in semi-insulating GaAs detected by optically polarized nuclear magnetic resonance in a magnetic field of 4.7 T. The main features of the observed shift are a systematic change in the absolute shift value as the... (Read more)
- 30. Phys. Rev. B 74, 035213 (2006) , “Bound exciton states of isoelectronic centers in GaAs:N grown by an atomically controlled doping technique”, Takashi Kita and Osamu WadaWe have studied bound exciton states of isoelectronic centers of nitrogen-doped GaAs by photoluminescence (PL) spectroscopy. The nitrogen doping has been performed in an atomically controlled way using the (3×3) nitrogen stable surface on GaAs(001), which has succeeded in forming a series of... (Read more)
- 31. Phys. Rev. B 74, 035208 (2006) , “Ultranarrow photoluminescence transitions of nitrogen cluster bound excitons in dilute GaAsN”, D. Karaiskaj, A. Mascarenhas, M. Adamcyk, E. C. Young, and T. TiedjeHigh resolution photoluminescence spectroscopy on heavily doped GaAs:N reveals the existence of excitons bound to a nitrogen cluster. The observed transitions are exceedingly sharp, similar to those observed for excitons bound to nitrogen pairs in high quality GaAs with the narrowest transition... (Read more)
- 32. Phys. Rev. B 73, 33201 (2006) , “Manganese on various lattice sites in (Ga,Mn)As investigated using electron paramagnetic resonance”, T. WeiersThe differences between variously doped and grown samples of manganese-doped GaAs have been studied and set in relation to the magnetic and electronic properties of these materials. For interion exchange and contrary to the resolved hyperfine and crystal field contributions from the ionized acceptor... (Read more)
- 33. Phys. Rev. B 73, 205205 (2006) , “Photoluminescence from the nitrogen-perturbed above-bandgap states in dilute GaAs1–xNx alloys: A microphotoluminescence study”, P. H. Tan, X. D. Luo, Z. Y. Xu, Y. Zhang, A. Mascarenhas, H. P. Xin, C. W. Tu, and W. K. GeUsing microphotoluminescence (µ-PL), in dilute N GaAs1–xNx alloys, we observe a PL band far above the bandgap E0 with its peak energy following the so-called E+ transition, but with contribution from perturbed... (Read more)
- 34. Phys. Rev. B 73, 125204 (2006) , “Optically detected magnetic resonance studies of point defects in Ga(Al)NAs”, I. P. Vorona, T.Mchedlidze, D. Dagnelund, I. A. Buyanova, W. M. Chen, K. K?hlerAn optically detected magnetic resonance (ODMR) study of Ga(Al)NAs alloys grown by molecular beam epitaxy on GaAs substrates is presented. A number of grown-in defects were observed which act as nonradiative recombination centers. A detailed analysis of experimental data using a spin Hamiltonian... (Read more)
- 35. Phys. Rev. Lett. 97, 226401 (2006) , “Quasiparticle Corrections to the Electronic Properties of Anion Vacancies at GaAs(110) and InP(110)”, Magnus Hedström, Arno Schindlmayr, Günther Schwarz, and Matthias SchefflerWe propose a new method for calculating optical defect levels and thermodynamic charge-transition levels of point defects in semiconductors, which includes quasiparticle corrections to the Kohn-Sham eigenvalues of density-functional theory. Its applicability is demonstrated for anion vacancies at... (Read more)
- 36. Physica B 373, 182-193 (2006) , “Electron–nuclear double resonance and dynamic nuclear polarization in GaAs in the regime of the quantum Hall effect”, E. Olshanetsky, J.D. Caldwell, A.E. Kovalev, C.R. Bowers, J.A. Simmons , J.L. RenoElectron spin resonance (ESR) and electron-nuclear double resonance experiments were performed in the 2D electron systems of GaAs/AlxGa1−xAs quantum well and heterojunction samples in the vicinity of the unity filling factor in the regime of the quantum Hall effect. As is well known, the ESR... (Read more)
- 37. AIP Conf. Proc. 772, 147 (2005) , American Institute of Physics , “Deep levels in osmium doped p-type GaAs grown by metal organic chemical vapor deposition”, M. Zafar Iqbal, A. Majid, A. Dadgar, and D. BimbergResults of a preliminary study on deep level transient spectroscopy (DLTS) investigations of osmium (Os) impurity in p-type GaAs, introduced in situ during MOCVD crystal growth, are reported for the first time. Os is clearly shown to introduce two prominent deep levels in the lower half-bandgap of GaAs at energy positions Ev + 0.42 eV (OsA) and Ev + 0.72 eV (OsB). A minority-carrier emitting defect feature observed in the upper half-bandgap is shown to consist of a band of Os-related deep levels with a concentration significantly higher than that of the majority carrier emitting deep levels. Detailed data on the emission rate signatures and related parameters of the Os-related deep levels are reported. ©2005 American Institute of Physics (Read more)
- 38. AIP Conf. Proc. 772, 143 (2005) , American Institute of Physics , “Deep levels in Ruthenium doped p-type MOCVD GaAs”, A. Majid, M. Zafar Iqbal, A. Dadgar, and D. BimbergRuthenium is introduced into GaAs during epitaxial growth by MOCVD. Preliminary results of DLTS investigation of the defect states associated with this 4d transition-metal impurity are reported for the first time. At least three deep levels are identified with Ru in the lower half-bandgap of GaAs at energy positions Ev + 0.38 eV, Ev + 0.52 eV and Ev + 0.65 eV, the last with a relatively higher concentration than the first two. At least one Ru-related deep level is observed in the upper half-bandgap at Ec – 0.66 eV with a significantly high concentration. Emission rate signatures and associated characteristics of all these defect levels are reported. The Ev + 0.65 eV level is found to exhibit an electric field dependent thermal emission characteristic. ©2005 American Institute of Physics (Read more)
- 39. AIP Conf. Proc. 772, 121 (2005) , “ESR Study of Zn-codoping Effect on the Luminescence Efficiency of the Er-2O Center in GaAs:Er,O”, M. Yoshida, K. Hiraka, H. Ohta, Y. Fujiwara, A. Koizumi, and Y. TakedaESR measurements of Zn-codoped GaAs:Er,O have been performed at 9.49 GHz. Several anisotropic ESR signals (A, B, and C) are observed. We found that the intensity of the C center decreases together with the decrease of the PL intensity by increasing the doping amount of Zn, while the changes of the... (Read more)
- 40. Appl. Phys. Lett. 87, 252118 (2005) , “"EL2" revisited: Observation of metastable and stable energy levels of EL2 in semi-insulating GaAs”, D. Kabiraj, S. GhoshBy using a combination of detailed experimental studies, we identify the metastable and stable energy levels of EL2 in semi-insulating GaAs. These results are discussed in light of the recently proposed models for EL2 in GaAs. ©2005 American Institute of Physics ... (Read more)
- 41. J. Appl. Phys. 98, 083709 (2005) , American Institute of Physics , “Osmium impurity-related deep levels in n-type GaAs”, A. Majid, M. Zafar Iqbal, A. Dadgar and D. BimbergThe 5d transition-metal impurity, osmium, has been incorporated during the growth of n-type GaAs epitaxial layers using low-pressure metal-organic chemical-vapor deposition to characterize defect states associated with this heavy and, therefore, thermally stable dopant impurity.... (Read more)
- 42. J. Appl. Phys. 97, 23909 (2005) , “Electron spin resonance study of Zn-codoping effect on the local structure of the Er-related centers in GaAs:Er,O”, Makoto Yoshida, Kensaku Hiraka, Hitoshi Ohta, Yasufumi Fujiwara, Atsushi Koizumi, Yoshikazu TakedaElectron spin resonance (ESR) measurements of Zn-codoped GaAs:Er,O grown by organometallic vapor phase epitaxy have been performed at 9.49 GHz. Several anisotropic ESR signals (named as A, B, and C) are observed. The angular and temperature dependences of the A, B, and C signals are quite... (Read more)
- 43. Phys. Rev. B 72, 115205 (2005) , “Defect identification in the AsGa family in GaAs”, H. Overhof and J.-M. SpaethAb initio total-energy calculations are presented for intrinsic defects in GaAs with a particular emphasis on hyperfine interactions in order to clarify the atomic structure of the various AsGa-related defects. For the AsGa-X2 defect complex the... (Read more)
- 44. Semiconductors 39, 493 (2005) , “Magnetic Ordering Effects in Heavily Doped GaAs:Fe Crystals”, B. P. Popov, V. K. Sobolevski?, E. G. Apushkinski?, V. P. Savel'evThe exchange coupling of Fe centers in GaAs crystals is studied by electron spin resonance (ESR). Transitions to a superparamagnetic state and to an impurity ferromagnetism domain are analyzed. A study of a system of single-domain magnetically ordered regions in GaAs:Fe with the transition to a ferromagnetic state occurring at the temperature T C1 = 460 K is described. It is shown that impurity ferromagnetism with a transition temperature T C2 of 60 K in a disordered system of Fe centers randomly distributed among superparamagnetic regions exists in GaAs:Fe. (Read more)
- 45. J. Appl. Phys. 96, 4189 (2004) , “Electron spin resonance study of GaAs:Er,O grown by organometallic vapor phase epitaxy”, Makoto Yoshida, Kensaku Hiraka, Hitoshi Ohta, Yasufumi Fujiwara, Atsushi Koizumi, Yoshikazu TakedaElectron spin resonance (ESR) measurements of GaAs:Er,O grown by organometallic vapor phase epitaxy have been performed at 9.49 GHz from 4.5 to 13 K. Several anisotropic ESR signals (A, B, C, and D) are observed, which is consistent with the previous reports. We... (Read more)
- 46. Physica E 21, 928-932 (2004) , “Electron spin resonance and nuclear spin pumping in 2DEG quantum Hall system”, S. Teraoka , A. Numata , S. Amaha , K. Ono , S. TaruchaWe prepare a microwave electron spin resource (ESR) cavity for detecting a response from a 2DEG in an n-AlGaAs/GaAs. The response is obtained as a change in the longitudinal resistance (Δρxx) in v=3 quantum Hall region, particularly as a peak in Δρxx for resonance. We use the data of ESR to evaluate the g-factor and the lower bound for dephasing time. The resonance magnetic field suffers from nuclear spin effects via the hyperfine coupling, resulting in the ESR peak shift. We find the ESR peak shift or Overhauser shift decays with two time constants, suggesting the existence of two different origins for the relaxation. (Read more)
- 47. Rev. Sci. Instrum. 75, 4781 (2004) , “W-band Fabry–Pérot microwave reasonators for optical detected electron paramagnetic resonance and electron nuclear double resonance of paramagnetic defects in solids”, I. Tkach, U. Rogulis, S. Greulich-Weber, and J.-M. SpaethThe designs of W-band (~95 GHz) Fabry–Pérot microwave resonators for optically detected electron paramagnetic resonance (ODEPR) and electron nuclear double resonance (ODENDOR) as well as the ODEPR/ODENDOR spectrometer are described. The Fabry–Pérot resonator was... (Read more)
- 48. J. Appl. Phys. 94, 3115 (2003) , American Institute of Physics , “Characteristics of deep levels associated with rhodium impurity in n-type GaAs”, M. Zafar Iqbal, A. Majid, Shah Haidar Khan, Akbar Ali, Nasim Zafar, A. Dadgar and D. Bimberg.,Deep levels have been characterized in n-type GaAs crystalline films grown by metalorganic chemical vapor deposition, doped in situ with 4d transition metal, rhodium, using the deep level transient spectroscopy (DLTS) technique. Two prominent broad bands of deep levels are found... (Read more)
- 49. Phys. Rev. B 68, 193204 (2003) , “Arsenic-antisite defect in GaAs: Multiplicity of charge and spin states”, D. J. ChadiWe find that the As-antisite defect in GaAs which is the source of the stable EL2 and metastable EL2* centers can exist in at least eight different combinations of charge and structural states, twice as many as currently envisaged. In particular, results from first-principles... (Read more)
- 50. Phys. Rev. B 67, 33301 (2003) , “Electron spin coherence in semiconductors: Considerations for a spin-based solid-state quantum computer architecture”, Rogerio de Sousa and S. Das SarmaWe theoretically consider coherence times for spins in two quantum computer architectures, where the qubit is the spin of an electron bound to a P donor impurity in Si or within a GaAs quantum dot. We show that low-temperature decoherence is dominated by spin-spin interactions, through spectral... (Read more)
- 51. Phys. Rev. B 67, 165325 (2003) , “Temperature dependence and mechanism of electrically detected ESR at the v=1 filling factor of a two-dimensional electron system”, Eugene Olshanetsky, Joshua D. Caldwell, Manyam Pilla, Shu-chen Liu, Clifford R. Bowers, Jerry A. Simmons, John L. RenoElectrically detected electron spin resonance (EDESR) signals were acquired as a function of temperature in the 0.3–4.2 K temperature range in an AlGaAs/GaAs multiple-quantum-well sample at the = 1 filling factor at 5.7 T. In the particular sample studied, the linewidth is approximately... (Read more)
- 52. Physica B 340, 362 (2003) , Elsevier , “Deep levels in rhodium-doped p-type MOCVD GaAs ”, A. Majid, M. Zafar Iqbal, A. Dadgar, D. Bimbergp-type GaAs epilayers grown by metal-organic chemical vapour deposition (MOCVD) technique, doped in situ with rhodium (Rh) impurity, have been studied by deep level transient spectroscopy (DLTS). A composite peak consisting of emission signals from at least two deep levels in the lower-half band gap is identified with Rh. This peak is resolved using double-correlation DLTS (DDLTS) measurements, providing the clear energy positions of the Rh-related deep levels as Ev+0.35 eV and Ev+0.51 eV. Emission rate signatures and other parameters are reported for these deep levels. They are observed to show electric-field dependent emission signatures. No significant minority carrier (electron) deep level could be clearly identified with Rh due to the presence of significant inadvertent features in the injection DLTS spectrum. Results are compared with our earlier study of Rh-doped, n-type, MOCVD GaAs. (Read more)
- 53. Physica B 340, 358 (2003) , “Osmium related deep levels in n-type GaAs ”, M. Zafar Iqbal, A. Majid, A. Dadgar, D. BimbergDeep levels due to 5d transition metal, osmium (Os), in n-type GaAs epitaxial layers grown by metal-organic vapour-phase epitaxy are investigated using deep level transient spectroscopy (DLTS). Two clear and prominent peaks are observed in majority carrier (electron) emission spectra in GaAs:Os samples in addition to a weaker, broad feature at higher temperatures, which are absent in the Os-free, reference samples. The well-resolved, prominent peaks are attributed to deep levels associated with Os impurity having activation energies Ec−0.28 eV and Ec−0.41 eV at a junction electric field of not, vert, similar1.4×105 V/cm. Both of these peaks are found to be field dependent. Detailed data on emission rate signatures, apparent electron capture cross-sections and defect concentrations are reported for these levels. No Os-related deep level peaks could be clearly delineated in minority-carrier injection DLTS, at this stage, although some evidence is found for a low-energy deep level band. (Read more)
- 54. Physica E 17, 320-321 (2003) , “Temperature dependence of electrically detected ESR at filling factor ν=1 in a 2DEG”, Eugene Olshanetsky, Manyam Pilla, Joshua D. Caldwell, Clifford R. Bowers, Jerry A. Simmons and John L. RenoElectrically detected electron spin resonance (ESR) was measured as a function of temperature for 0.3–4.2 K in a AlGaAs/GaAs multiple quantum well sample at filling factor ν=1. The ESR amplitude exhibits a maximum at about 2.2 K and vanishes with increased or decreased temperature. To... (Read more)
- 55. Polyhedron 22, 225-233 (2003) , “Study on guanidino–carboxylate interactions in copper(II) ternary complexes of guanidinoacetic acid with glutamic and aspartic acids”, Jussara Lopes de Miranda and Judith FelcmanThe possibility of occurrence of biological relevant guanidino–carboxylate interactions was investigated in ternary systems involving guanidinoacetic (Gaa) and glutamic acid (Glu), aspartic acid (Asp) or glycine (Gly). The study was done in solution using potentiometry, ultraviolet visible... (Read more)
- 56. Semiconductors 37, 918 (2003) , “The Relaxation of the Neutral State of Manganese in Gallium Arsenide”, V. F. Masterov, K. F. Shtel'makh, V. P. Maslov, S. B. Mikhrin, B. E. SamorukovResults of investigations of the longitudinal magnetic relaxation of the neutral state of the Mn0 center in GaAs are presented. Relaxation mechanisms were determined from the broadening of the electron-spinresonance line in the temperature range of 3.4–8.2 K and from the variation in the nuclear relaxation rate in the range of 36–310 K. The nuclear relaxation investigation demonstrates that the electron relaxation is governed by the interaction between lattice vibrations and local vibrations of the center. This allows one to represent the electron relaxation at low temperatures as the consequence of anharmonicity of local vibrations of the electron dipole moment of the Mn0 center. (Read more)
- 57. Semiconductors 37, 872 (2003) , “ESR of Interacting Manganese Centers in Gallium Arsenide”, K. F. Shtel'makh, M. P. Korobkov, I. G. OzerovESR of Mn-doped GaAs is studied. The results indicate the presence of an interstitial impurity state in GaAs:Mn which is involved in the Coulomb interaction with the substitutional Mn states. Analysis of the temperature variations of ESR spectra and the values of the g factor shows that the interstitial center has a d5 electron configuration. The substitutional Mn create a strong random crystal field at the interstitial Mn ion. The results can be explained by assuming the existence of a nonzero dipole moment in the neutral state of Mn. (Read more)
- 58. Phys. Rev. B 66, 45201 (2002) , “Single ion anisotropy of Mn-doped GaAs measured by electron paramagnetic resonance”, O. M. Fedorych, E. M. Hankiewicz, Z. Wilamowski, J. SadowskiAn electron-paramagnetic-resonance (EPR) study of molecular-beam-epitaxy-grown Mn-doped GaAs is presented. The resolved fine structure in insulating Ga1-xMnxAs allows us to evaluate the crystal-field parameters of the spin Hamiltonian. The exchange narrowing of the structure,... (Read more)
- 59. Phys. Rev. B 64, 41307 (2001) , “Gate-controlled electron spin resonance in GaAs/AlxGa1-xAs heterostructures”, H. W. Jiang, Eli YablonovitchThe electron spin resonance (ESR) of two-dimensional electrons is investigated in a gated GaAs/AlGaAs heterostructure. We found that the ESR resonance frequency can be tuned by means of a gate voltage. The front and back gates of the heterostructure produce opposite g-factor shift, suggesting that... (Read more)
- 60. Phys. Rev. B 64, 201308 (2001) , “Magnetic-field pinning of a dynamic electron-spin-resonance line in a GaAs/AlxGa1-xAs heterostructure”, Chris Hillman, H. W. JiangElectrically detected electron spin resonance (ESR) is used to study the hyperfine interaction of the two-dimensional electrons and the nuclei of the host lattice in a GaAs/AlGaAs heterostructure. Under microwave and radio-frequency double excitations, we have observed that the ESR line can be... (Read more)
- 61. Physica B 308, 816 (2001) , Elsevier Science , “Rhodium-related deep levels in n-type MOCVD GaAs ”, M. Zafar Iqbal, A. Majid, S. Haidar Khan, Akbar Ali, Nasim Zafar, A. Dadgar and D. BimbergPreliminary results on the study of deep levels associated with 4d-transition metal, rhodium, in crystalline GaAs grown by metal-organic chemical vapour deposition (MOCVD) technique are reported for the first time. Deep level transient spectroscopy on n-type GaAs doped in situ with Rh during MOCVD growth reveals a broad majority carrier emission peak. The peak corresponds to a band of deep levels extending over the energy range 0.57–0.65 eV below the conduction band edge with lower-energy states having lower electron capture cross-sections. The deep levels show a pronounced dependence of electron emission rate on the junction electric field. Minority carrier (hole) emission spectra at zero bias show a pronounced Rh-related deep-level peak with a low-temperature shoulder. The dominant level in the lower half-gap is found to have a position Ev+0.44 eV, with a field-dependent emission rate signature. (Read more)
- 62. Physica B 308-310, 753-756 (2001) , “On the problem of the EL2 structure in semi-insulating GaAs: high-frequency ODEPR/ODENDOR measurements in W-band”, I. Tkach, K. Krambrock and J. -M. SpaethFor almost two decades the structure model of the EL2 defect in semi-insulating (SI) GaAs has been controversially discussed. Neither the isolated AsGa with Td symmetry, nor the AsGa–Asi pair model nor any other AsGa-related defect model could be unambiguously established. The reason was that... (Read more)
- 63. Physica B 308-310, 749-752 (2001) , “Magneto-optical and ODEPR investigations of native defects in substrate-free LT-MBE grown GaAs”, I. Tkach, K. Krambrock, C. Steen, P. Kiesel and J. -M. SpaethAs-grown substrate-free LT-GaAs (200°C) and annealed samples (up to 660°C) have been investigated with magnetic circular dichroism of absorption (MCDA) and optically detected electron paramagnetic resonance (MCDA-EPR) in K- and W-bands. MCDA-EPR spectra of all samples reveal several... (Read more)
- 64. Physica B 294-295, 298-301 (2001) , “High field magnetoresistance and ESR measurements on Ni stripes on GaAs substrate”, A. Matsuo, M. Taki, S. A. Haque, Y. Yamamoto, T. Kikutani, S. Yamada, H. Nojiri, M. Motokawa and H. HoriNi nanowires fabricated on a GaAs substrate, which have width narrower than 500 nm and thickness 50 nm, showed an antiferromagnetic-like domain structure. Many Ni nanowires fabricated on GaAs using the electron beam lithography technique have been studied by electron spin resonance (ESR). Splitting... (Read more)
- 65. Physica E 10, 57-61 (2001) , “Millimeter wave and DC investigations of spin effects in the 2DES of AlGaAs/GaAs”, R. Meisels, K. Dybko, F. Ziouzia, F. Kuchar, R. Deutschmann, G. Abstreiter, G. Hein and K. PierzThe spin properties of the 2DES in AlGaAs/GaAs heterostructures are studied via the electron spin resonance (ESR) of conduction electrons and via the temperature dependence of the DC-σxx(B) conductivity component. The ESR is investigated at integer (ν=1) and fractional filling factors... (Read more)
- 66. Physica E 10, 399-402 (2001) , “Codoping effect of O2 into Er-doped InP epitaxial layers grown by OMVPE”, H. Ohta, C. Urakawa, Y. Nakashima, J. Yoshikawa, T. Koide, T. Kawamoto, Y. Fujiwara , Y. TakedaThe temperature dependence of ESR in InP:Er and the O2 codoping effect in InP:Er have been studied by X-band ESR measurement at low temperature. The ESR at around g=6, which corresponds to Er3+ site with Td symmetry, lost it's intensity quickly as the temperature is increased and disappeared above... (Read more)
- 67. Physica E 10, 395-398 (2001) , “ESR study of GaAs:Er codoped with oxygen grown by organometallic vapor phase epitaxy”, J. Yoshikawa, C. Urakawa, H. Ohta, T. Koide, T. Kawamoto, Y. Fujiwara and Y. TakedaX-band ESR measurements of GaAs:Er grown at 543°C by organometallic vapor phase epitaxy (OMVPE) with and without an additional O2 flow (samples I and II, respectively) have been performed at 3.5 K. Sample I shows an isotropic ESR signal around g=6 together with several anisotropic ESR signals... (Read more)
- 68. Physica E 10, 175-180 (2001) , “Monitoring the sign reversal of the valence band exchange integral in (Ga,Mn)As”, W. Heimbrodt, Th. Hartmann, P. J. Klar, M. Lampalzer, W. Stolz, K. Volz, A. Schaper, W. Treutmann, H. -A. Krug von Nidda, A. Loidl, T. Ruf and V. F. SapegaWe report the successful growth of magnetic Ga1−xMnxAs layers on (1 0 0) GaAs substrates by metal-organic vapour-phase epitaxy. Depending on the growth parameters, two different magnetic phases of Ga1−xMnxAs can be grown. (i) At low Mn-concentrations, Ga1−xMnxAs alloys are... (Read more)
- 69. Phys. Rev. B 61, 5637 (2000) , “Electron spin resonance of the two-dimensional electron system in AlxGa1-xAs/GaAs at subunity filling factors”, R. Meisels, I. Kulac, F. Kuchar, M. KriechbaumThe electron spin resonance (ESR) of a two-dimensional electron system (2DES) in AlxGa1-xAs/GaAs in the regime of fractional filling (ν<1) of the lowest Landau level is investigated by a photoconductivity technique at millimeter wave frequencies. By performing the experiments... (Read more)
- 70. Physica B 291, 270-274 (2000) , “An investigation of the optical spectra and EPR parameters of vanadium in III–V semiconductors (GaAs, GaP, InP)”, Jia-Jun Chen and Mao-Lu DuAs there is strong covalence in III–V semiconductors, the effect of the difference between the t2g orbit and eg orbit must be considered in their electric structure. In this paper we present a modified Sugano–Tanabe scheme and give the energy matrix of the d2 system and the g-factor... (Read more)
- 71. Physica E 6, 798-801 (2000) , “An experimental and theoretical study of the electron spin resonance mechanism in AlGaAs/GaAs”, R. Meisels, F. Kuchar and M. KriechbaumThe electron spin resonance (ESR) of the 2DES in AlGaAs/GaAs is investigated at millimeterwave frequencies and is shown to be dominantly a magnetic dipole transition. Strain-induced contributions to the electric dipole transition rate can be neglected. The origin of the change of the resistance due... (Read more)
- 72. J. Magn. Reson. 136, 207-210 (1999) , “A Cryogenically Coolable Microwave Limiter”, George A. Rinard, Richard W. Quine , Gareth R. EatonA microwave (ca. 3 GHz) limiter, constructed using a GaAs PIN diode and microstrip impedance transformation circuit, limited 300-ns long 11-W microwave pulses to 70 mW at ca. 4.2 K. This limiter was implemented in a pulsed electron paramagnetic resonance (EPR) spectrometer to protect a low-noise microwave preamplifier from the high-power pulses. (Read more)
- 73. Jpn. J. Appl. Phys. 37, 1939-1944 (1999) , “Role of the EL2 Center on the Formation of Metastable Hydrogen-related Defects (M3/M4) in n-GaAs”, T. Shinagawa, T. OkumuraHydrogen-related metastable defects (M3/M4) in n-GaAs were studied in relation to the EL2 center. We found that the M3/M4 defects were observed only in the crystals containing the EL2 center in the as-grown state after exposure to a hydrogen plasma. The EL3 level, which was tentatively assigned as... (Read more)
- 74. Mater. Res. Soc. Symp. Proc. 573, 107 (1999) , “ELECTRICAL AND OPTICAL STUDY OF CHARGE TRAPS AT PASSIVATED GaAs SURFACES”, Y. Mochizuki
- 75. Phys. Rev. B 60, 8304 (1999) , “Mn impurity in Ga1-xMnxAs epilayers”, J. Szczytko, A. Twardowski, K. ?wi?tek, M. Palczewska, M. Tanaka, T. Hayashi, K. AndoElectron paramagnetic resonance was measured in Ga1-xMnxAs/GaAs epilayers with 0.002<~x<~0.01. Data were taken as a function of magnetic field orientation at low temperatures. The observed spectra were attributed to ionized Mn acceptor A-. No neutral Mn... (Read more)
- 76. Physica B 273-274, 7-14 (1999) , “Self-interstitials in semiconductors: what we are learning from interstitial Zn in ZnSe”, G. D. Watkins , K. H. ChowInterstitial Zn+i has been observed in ZnSe by optical detection of EPR to be on-center in either Td interstitial site – that surrounded by four Se atoms, (Zni)+Se, or by four Zn atoms, (Zni)+Zn. This can be understood by a simple universal model which predicts stability for an interstitial... (Read more)
- 77. Solid State Commun. 110, 593-598 (1999) , “Generation of EL2 defects by a 6-MeV proton irradiation of semi-insulating GaAs”, S. A. Goodman, F. K. Koschnick, Ch. Weber, J. -M. Spaeth and F. D. AuretThe defects introduced in a bulk semi-insulating (SI) GaAs by a 6-MeV proton irradiation at 300 K were investigated with the electron paramagnetic resonance (EPR) detected via the magnetic circular dichroism of the optical absorption. EL2 defects (EL20 and EL2+) are introduced by proton irradiation... (Read more)
- 78. J. Appl. Phys. 84, 6782 (1998) , “Electron spin resonance of Er–oxygen complexes in GaAs grown by metal organic chemical vapor deposition”, T. Ishiyama, E. Katayama, K. Murakami, K. Takahei, A. TaguchiWe have performed electron spin resonance (ESR) measurements on Er-doped GaAs grown with oxygen codoping by metal organic chemical vapor deposition. An isotropic line (an effective g value, g = 5.95) which had been already reported was observed in samples without oxygen codoping. On... (Read more)
- 79. Phys. Rev. B 58, 7707 (1998) , “Optically detected magnetic resonance study of an arsenic-antisite–arsenic-vacancy complex in GaAs”, F. K. Koschnick, K.-H. Wietzke, and J.-M. SpaethAn arsenic-antisite-related defect produced in n-type GaAs by 2 MeV electron irradiation was investigated using magnetic circular dichroism of the optical absorption (MCDA), MCDA-detected electron paramagnetic resonance (MCDA-EPR), and MCDA-detected electron-nuclear double resonance (MCDA-ENDOR). In... (Read more)
- 80. J. Cryst. Growth 174, 751-756 (1997) , “Investigation of the interfacial quality and the influence of different substrates in ZnSe homoepitaxy”, H. Wenisch, T. Behr, J. Kreissl, K. Sch?ll, D. Siche, H. Hartmann , D. HommelZnSe substrates grown by the seeded chemical vapour transport and recrystallization as well as by the Bridgman method are compared for their use in molecular beam epitaxy. Intrinsic and extrinsic defects were analysed by low-temperature photoluminescence and especially by... (Read more)
- 81. Nucl. Instrum. Methods Phys. Res. A 395, 76-80 (1997) , “Optical deep-level transient characterisation of gamma-irradiated semi-insulating gallium arsenide”, Say Teng Lai, Dimitri Alexiev, Claude Schwab , Ian DonnellyA unique optical deep-level transient conductance spectroscopy (ODLTCS) technique has been employed for studying undoped semi-insulating (SI) GaAs material. In the undoped SI GaAs, the Fermi-level first shifts towards gamma irradiation of the conduction band at low γ fluence and then towards... (Read more)
- 82. Phys. Rev. B 56, 7422 (1997) , “High-field spin resonance of weakly bound electrons in GaAs”, M. Seck, M. Potemski, and P. WyderElectron spin resonance (ESR) of shallow donor electrons in n-type GaAs has been observed by means of direct detection of microwave absorption at magnetic fields of 6–11 T. The ESR structure is smeared out over a magnetic field range of up to 1 T. The line shape is strongly asymmetric and depends... (Read more)
- 83. Phys. Rev. B 56, 10221 (1997) , “Optically detected electron-paramagnetic-resonance investigations of the substitutional oxygen defect in gallium arsenide”, F. K. Koschnick, M. Linde, M. V. B. Pinheiro, and J.-M. SpaethThe substitutional oxygen defect in GaAs has been investigated with magnetic circular dichroism of the absorption, optically detected electron paramagnetic resonance, and optically detected electron-nuclear double resonance (ODENDOR). The ODENDOR spectra can be explained with an oxygen atom... (Read more)
- 84. Rev. Sci. Instrum. 68, 2511 (1997) , “Sensitivity enhancement in magnetic circular dichroism of absorption-detected electron paramagnetic resonance with a mirror cavity”, F. K. KoschnickA mirror cavity was developed to improve the signal to noise (S/N) ratio of the measurement of the magnetic circular dichroism of the absorption (MCDA) and of the MCDA-detected electron paramagnetic resonance (EPR). In this cavity the measurement light beam passes through the sample several times... (Read more)
- 85. Solid State Commun. 102, 715-720 (1997) , “Nuclear spin relaxation in AlGaAs/GaAs heterostructures observed via optically detected magnetic resonance (ODMR) experiments”, M. Schreiner, H. Pascher, G. Denninger, S. A. Studenikin, G. Weimann and R. LöschThe resonant field at which an electron spin resonance (ESR) occurs may be shifted by an effective magnetic field, which is due to spin polarized nuclei. This shift, known as Overhausershift, is caused by the field of all polarized nuclei without respect to their isotopic number. Irradiation of the... (Read more)
- 86. Solid State Commun. 101, 219-223 (1997) , “Compensation center of Cr3+ in GaAs codoped with Cr and In for obtaining a semi-insulating property”, Y. J. Park, T. H. Yeom, I. -W. Park, S. H. Choh , S. -K. MinThe dependences of Cr2+ and Cr3+ electron paramagnetic resonance (EPR) signals as a function of Cr concentration have been investigated in conjunction with clarifying the atomic configuration for obtaining semi-insulating properties in a vertical gradient freeze (VGF)-GaAs single crystal codoped... (Read more)
- 87. Mater. Sci. Eng. B 42, 213-216 (1996) , “Investigation of deep-level defects in semi-insulating GaAs and InP by analysis of photo-induced current transients”, P. Kamiński, R. Ćwirko, M. Palczewska and R. KozłowskiA new digital approach to PICTS technique was applied to study deep levels in undoped SI GaAs and Fe-doped InP. For SI Fe-doped InP, the 0.64-eV trap related to Fe2 + /Fe3 + acceptor level as well as the 0.53-eV trap attributed to a native defect, were observed. For SI undoped GaAs, three traps: T1... (Read more)
- 88. Phys. Rev. B 54, 10508 (1996) , “Neutral manganese acceptor in GaP: An electron-paramagnetic-resonance study”, J. Kreissl, W. Ulrici, M. El-Metoui, A.-M. Vasson, A. Vasson, A. GavaixIn order to clarify the nature of the neutral Mn acceptor in GaP, we have carried out optical-absorption and electron-paramagnetic-resonance (EPR) experiments using both conventional and thermally detected EPR on semi-insulating GaP:Mn. In thermal equilibrium at low temperatures, all the manganese... (Read more)
- 89. Proc. SPIE 2780, 133-136 (1996) , “Digital analysis of photo-induced current transients in semi-insulating GaAs and InP”, Pawel Kaminski, Michal Pawlowski, Robert Cwirko, M. Palczewska, Roman KozlowskiDigital PITS technique was applied to study deep-level defects in semi-insulating GaAs and InP. The studies were completed by measurements of ESR spectra on the same wafers.... (Read more)
- 90. Prog. Surf. Sci. 51, 263-408 (1996) , “Scanning tunneling microscopy study of fullerenes”, T. Sakurai, X. -D. Wang, Q. K. Xue, Y. Hasegawa, T. Hashizume and H. ShinoharaScanning tunneling microscopy investigations of adsorption and film growth of various fullerenes on semiconductor and metal surfaces are reviewed. The fullerenes being studied are C60, C70, C84, Sc@C82 and Y@C82 and the substrates being used for adsorption are Si (111), Si (100), Ge (111), GaAs... (Read more)
- 91. Semiconductors 30, 552 (1996) , “Anomalous excitation in the ESR spectrum of the Fe3+ ion in GaAs”, A. A. Ezhevski?, S. J. H. M. van Gisbergen, C. A. J. Ammerlaan
- 92. Surf. Sci. 361-362, 55-58 (1996) , “Electron spin resonance in AlGaAs/GaAs in the regime of fractional filling”, R. Meisels, I. Kulac, G. Sundaram, F. Kuchar, B. D. McCombe, G. Weimann , W. SchlappWe have studied the electron spin resonance (ESR) at millimeterwave frequencies in high mobility AlGaAs/GaAs samples for the first time at filling factors v < 1 outside the v = 1 resistance minimum. The magnetic field dependence of the ESR measured at T = 1.6 K agrees with the calculations made... (Read more)
- 93. J. Appl. Phys. 78, 2411 (1995) , “Native defects in low-temperature GaAs and the effect of hydrogenation”, R. E. Pritchard, S. A. McQuaid, L. Hart, R. C. Newman, J. M?kinen, H. J. von Bardeleben, M. MissousA range of experimental techniques has been used to measure point defect concentrations in GaAs layers grown at low temperatures (250 °C) by molecular-beam epitaxy (LT-GaAs). The effects of doping on these concentrations has been investigated by studying samples containing shallow acceptors (Be)... (Read more)
- 94. Phys. Rev. B 51, 11117 (1995) , “Optical cross section for the EL2?EL2* metastable transformation”, N. Radić and B. ŠantićA simple and accurate method for the determination of the σ* optical cross section governing the EL2→EL2* transformation kinetics in GaAs is proposed. Previously reported σ* values are critically examined and corrected properly. The obtained absolute values of... (Read more)
- 95. Physica B 211, 23-29 (1995) , “Solid state experiments in megagauss fields”, N. Miura, H. Nojiri, Y. Shimamoto and Y. ImanakaThis paper presents a brief review on recent experiments of solid state physics in very high magnetic fields up to 550 T produced by electromagnetic flux compression and the single-turn coil technique, focusing on magneto-optical spectroscopy in semiconductors, low-dimensional magnetic systems and... (Read more)
- 96. J. Appl. Phys. 75, 7559 (1994) , “Observation of Cr3 + electron paramagnetic resonance center in GaAs co-doped with Cr and In”, Young Ju Park, Tae Ho Yeom, Suk-Ki Min, Il-Woo Park, Sung Ho ChohWe have observed a well-defined Cr3 + (3d3) electron paramagnetic resonance signal at 4 K in vertical gradient freeze semi-insulating GaAs single crystal through a co-doping with Cr and In. On the basis of analyzing the rotation pattern of the Cr3 + center,... (Read more)
- 97. Phys. Rev. B 50, 5189 (1994) , “Theoretical investigation of the dynamic process of the illumination of GaAs”, Ren Guang-bao, Wang Zhan-guo, Xu Bo, Zhou BingThe dynamic process of light illumination of GaAs is studied numerically in this paper to understand the photoquenching characteristics of the material. This peculiar behavior of GaAs is usually ascribed to the existence of EL2 states and their photodriven metastable states. To understand the... (Read more)
- 98. Phys. Rev. B 50, 2645 (1994) , “Magnetic-resonance studies of tellurium-doped AlxGa1?xAs”, M. Surma, Z. ?ytkiewicz, K. Fronc, M. Godlewski, P. Stallinga, B. MonemarAn ESR study performed on a thick AlxGa1-xAs epilayer with removed GaAs substrate is presented. The measurements were performed on LPEE-grown AlxGa1-xAs (x=0.41) heavily doped with Te. The detailed photo-ESR investigations of the light-induced conversion... (Read more)
- 99. Phys. Rev. B 50, 2645 (1994) , “Magnetic-rasonance studies of tellurium-doped AlxGa1-xAs”, M. Surma, Z. ?ytkiewicz, K. Fronc, M. Godlewski, P. Stallinga, B. MonemarAn ESR study performed on a thick AlxGa1-xAs epilayer with removed GaAs substrate is presented. The measurements were performed on LPEE-grown AlxGa1-xAs (x=0.41) heavily doped with Te. The detailed photo-ESR investigations of the light-induced conversion... (Read more)
- 100. Phys. Rev. B 49, 10999 (1994) , “Ligand ENDOR on substitutional manganese in GaAs”, S. J. C. H. M. van Gisbergen, A. A. Ezhevskii, N. T. Son, T. Gregorkiewicz, and C. A. J. AmmerlaanIn this paper Ga ligand electron-nuclear double resonance measurements are reported on the substitutional Mn2+ center in GaAs. On the basis of these experiments it is concluded that the Mn2+ center is substitutional on a Ga site. From the electron paramagnetic resonance... (Read more)
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