Optically Detected Magnetic Resonance of Donors in AlxGa1−x as with High AlAs Fraction

1987 ◽  
Vol 104 ◽  
Author(s):  
T. A. Kennedy ◽  
R. Magno ◽  
E. Glaser ◽  
M. G. Spencer

ABSTRACTOptical and magnetic properties of donors in high AlAs-fraction AlxGa1−x As have been determined using optically-detected magnetic resonance. Many samples exhibit a sharp resonance at g = 1.95 detected on midgap luminescence. One high-quality sample exhibits an exhange-broadened line which reveals a distribution in donor-acceptor pair separations on moderately deep emission. A second high-quality sample exhibits the donor ODMR on donor-to-shallow- acceptor photoluminescence.

1987 ◽  
Vol 104 ◽  
Author(s):  
K. M. Lee

ABSTRACTThe first experimental evidence of an isolated self-interstitial defect in an as-grown semiconductor is reported. An optically detected magnetic resonance spectrum observed in GaP [0] was identified as arising from a Ga selfinterstitial. The large isotropic hyperfine splittings (g = 2.003 (3), A(69Ga) = 741(5)×10−4 cm−1 and A(71Ga) -941[5]×10− 4 cm−1) revealed that a single Ga atom at a Td-symmetric site is the center of the defect. The interstitial nature is established by theoretical considerations. The spin dependent recombination process is attributed to a non-radiative donor-acceptor-pair process involving the Ga++ state which is in competition with a radiative (Odeg; - A° ) pair process and an electron capture process at O-donor.


1985 ◽  
Vol 46 ◽  
Author(s):  
K. M. Lee ◽  
L. C. Kimerling ◽  
M. D. Sturge

AbstractThe role of the luminescence killer center iron in GaP has been studied by the optically detected magnetic resonance technique. Observations of strong Fe°(3d5) and O0 resonance in the (Zn,O) donor-acceptor pair (DAP) and the 0.841 eV electron capture (EC) luminescence bands show that the luminescence killing action is via (Fe,O) DAP recombination.Two distinct but similar (Fe,O) DAP processes were detected: The (Fe0,O0) process with a slower recombination rate and (Fe0,O0*) process, with a faster effective relaxation rate, involving the oxygen excited state.


2000 ◽  
Vol 5 (S1) ◽  
pp. 507-513 ◽  
Author(s):  
B.J. Skromme ◽  
G.L. Martinez

Ion implantation is used to investigate the spectroscopic properties of Mg, Be, and C acceptors in GaN. Activation of these species is studied using low temperature photoluminescence (PL). Low dose implants into high quality undoped hydride vapor phase epitaxial (HVPE) material are used in conjunction with high temperature (1300 °C) rapid thermal anneals to obtain high quality spectra. Dramatic, dose-dependent evidence of Mg acceptor activation is observed without any co-implants, including a strong, sharp neutral Mg acceptor-bound exciton and strong donor-acceptor pair peaks. Variable temperature measurements reveal a band-to-acceptor transition, whose energy yields an optical binding energy of 224 meV. Be and C implants yield only slight evidence of shallow acceptor-related features and produce dose-correlated 2.2 eV PL, attributed to residual implantation damage. Their poor optical activation is tentatively attributed to insufficient vacancy production by these lighter ions. Clear evidence is obtained for donor-Zn acceptor pair and acceptor-bound exciton peaks in Zn-doped HVPE material.


2013 ◽  
Vol 827 ◽  
pp. 12-15
Author(s):  
Ya Fen Wu ◽  
Jiunn Chyi Lee

The optical properties of Cu-poor CuIn1-xGaxSe2 thin films with different gallium contents grown by co-evaporated technique were studied. Measurements of photoluminescence and photoreflectance were performed on the samples. The photoluminescence and photoreflectance emission peaks observed around 1.1 eV are attributed to donor-acceptor pair luminescence. These donor-acceptor pair emissions are considered to originate from relatively shallow acceptor and donor energy levels. With increasing gallium content, the emission peaks shift towards higher levels of photon energy, and the linewidths of the luminescence spectra for the samples become wider, which we attributes to the greater statistical disorder between indium and gallium. Moreover, the conversion efficiency of the CuIn1-xGaxSe2-based solar cells is obtained. The measured results coincide with the inference given by the photoluminescence spectra.


2004 ◽  
Vol 831 ◽  
Author(s):  
B. Monemar ◽  
P. P. Paskov ◽  
F. Tuomisto ◽  
K. Saarinen ◽  
M. Iwaya ◽  
...  

ABSTRACTWe report on deliberate O doping of GaN epitaxial layers during MOCVD growth, using H2O and CO2 as precursors. The photoluminescence spectra show a dominant 3.27 eV emission at 2 K known to be a donor-acceptor pair (DAP) transition. In our samples the intensity of this DAP spectrum correlates with the commonly observed 3.466 eV acceptor bound exciton (ABE) peak, suggesting these spectra are related to the same acceptor. The general correlation of these acceptor spectra with O concentration (as established with SIMS data) suggest that the acceptor is O-related, most likely a VGa-O complex. The concentration was measured with positron annihilation spectroscopy and found to be in the 1016 cm−3 -1017 cm−3 range in different samples. Considering previous results the identity of this residual acceptor is suggested to be a VGa-O-H complex. Previous suggestions that this acceptor is related to Mg, Si or C are discussed and found to be less likely.


1999 ◽  
Vol 595 ◽  
Author(s):  
B.J. Skromme ◽  
G.L. Martinez

AbstractIon implantation is used to investigate the spectroscopic properties of Mg, Be, and C acceptors in GaN. Activation of these species is studied using low temperature photoluminescence (PL). Low dose implants into high quality undoped hydride vapor phase epitaxial (HVPE) material are used in conjunction with high temperature (1300 °C) rapid thermal anneals to obtain high quality spectra. Dramatic, dose-dependent evidence of Mg acceptor activation is observed without any co-implants, including a strong, sharp neutral Mg acceptor-bound exciton and strong donor-acceptor pair peaks. Variable temperature measurements reveal a band-to-acceptor transition, whose energy yields an optical binding energy of 224 meV. Be and C implants yield only slight evidence of shallow acceptor-related features and produce dose-correlated 2.2 eV PL, attributed to residual implantation damage. Their poor optical activation is tentatively attributed to insufficient vacancy production by these lighter ions. Clear evidence is obtained for donor-Zn acceptor pair and acceptor-bound exciton peaks in Zn-doped HVPE material.


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