scholarly journals Исследование влияния структурных дефектов на спектры фотолюминесценции в n-3C-SiC

2019 ◽  
Vol 45 (11) ◽  
pp. 28
Author(s):  
А.А. Лебедев ◽  
И.П. Никитина ◽  
Н.В. Середова ◽  
Н.К. Полетаев ◽  
С.П. Лебедев ◽  
...  
Keyword(s):  
Single Crystals ◽  
Electron Irradiation ◽  
Epitaxial Layers ◽  
Radiation Defects ◽  
Twin Boundaries ◽  
Crystal Perfection ◽  
Pl Spectra ◽  
Donor Acceptor

AbstractPhotoluminescence (PL) spectra have been studied in 3 C -SiC/4 H -SiC heterostructures and 3 C ‑SiC single crystals. It was shown that epitaxial 3 C -SiC layers grown on 4 H -SiC substrates have a markedly poorer crystal perfection than do 3 C -SiC single crystals. It was found that doping with aluminum gives rise to a characteristic PL both in epitaxial layers and in 3 C -SiC single crystals. At the same time, the electron irradiation of epitaxial layers does not give rise to defect-related PL, in contrast to what is observed for single crystals. An assumption is made that the twin boundaries existing in epitaxial 3 C -SiC layers can serve as getters of radiation defects that are components of donor–acceptor pairs responsible for the “defect-related” PL.

Investigation of the Influence of Structural Defects on the PL Spectra in n-3C-SiC

2020 ◽  
Vol 1004 ◽  
pp. 278-283
Author(s):  
Lev V. Shakhov ◽  
Alexander A. Lebedev ◽  
Natalia. V. Seredova ◽  
Sergey P. Lebedev ◽  
Vitalii V. Kozlovski ◽  
...  
Keyword(s):  
Single Crystals ◽  
Structural Defects ◽  
Epitaxial Layers ◽  
Radiation Defects ◽  
Photoluminescence Spectra ◽  
Structural Perfection ◽  
Twin Boundaries ◽  
Pl Spectra ◽  
Donor Acceptor

The photoluminescence spectra were studied in 3C-SiC / 4H-SiC heterostructures and single crystals of 3C-SiC. It was shown that 3C-SiC epitaxial layers grown on 4H-SiC substrates have significantly less structural perfection than 3C-SiC single crystals. It was found that doping with aluminum leads to the appearance of characteristic photoluminescence (PL) both in the epitaxial layers and in 3C-SiC single crystals. At the same time, the irradiation of the epitaxial layers does not lead to the appearance of “defective PL (DFL), as is observed for single crystals. It was suggested that the twin boundaries existing in 3C-SiC epitaxial layers could serve as getters of radiation defects that are components of donor – acceptor pairs (DAP) responsible for DFL.

A New Deep Acceptor in Epitaxial Cubic SiC

1989 ◽  
Vol 162 ◽  
Author(s):  
J. A. Freitas ◽  
S. G. Bishop
Keyword(s):  
Thin Films ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Excitation Intensity ◽  
Acceptor Pair ◽  
Deep Acceptor ◽  
Intensity Dependence ◽  
Pl Spectra ◽  
Donor Acceptor ◽  
Donor Acceptor Pair

ABSTRACTThe temperature and excitation intensity dependence of photoluminescence (PL) spectra have been studied in thin films of SiC grown by chemical vapor deposition on Si (100) substrates. The low power PL spectra from all samples exhibited a donor-acceptor pair PL band which involves a previously undetected deep acceptor whose binding energy is approximately 470 meV. This deep acceptor is found in every sample studied independent of growth reactor, suggesting the possibility that this background acceptor is at least partially responsible for the high compensation observed in Hall effect studies of undoped films of cubic SiC.

scholarly journals Time-resolved Spectroscopy of the violet luminescence of undoped AlN

2005 ◽  
Vol 10 ◽  
Author(s):  
R. Freitag ◽  
K. Thonke ◽  
R. Sauer ◽  
D. G. Ebling ◽  
L. Steinke
Keyword(s):  
Epitaxial Layers ◽  
Yellow Luminescence ◽  
Acceptor Pair ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Violet Luminescence ◽  
Donor Acceptor ◽  
Violet Band ◽  
Donor Acceptor Pair

We report on the time-resolved luminescence of the defect-related violet band from undoped AlN epitaxial layers grown on sapphire and SiC. For both measurements in photoluminescence and in cathodoluminescence a decay of algebraic nature at long times is observed. This is typical for donor-acceptor pair transitions. We compare the behavior of this band to that of the generically yellow luminescence of GaN.

Temperature dependence of the optical properties in p-Cd0.96Zn0.04Te single crystals

2001 ◽  
Vol 16 (8) ◽  
pp. 2196-2199 ◽  
Author(s):  
H. Y. Lee ◽  
T. W. Kang ◽  
T. W. Kim
Keyword(s):  
Optical Properties ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Reasonable Agreement ◽  
Theoretical Calculations ◽  
Optoelectronic Devices ◽  
Activation Energies ◽  
Acoustic Parameters ◽  
Longitudinal Acoustic ◽  
Pl Spectra

Photoluminescence (PL) measurements were performed on p-Cd0.96Zn0.04Te single crystals to investigate the dependence of the excitons on temperature. The activation energies and the longitudinal acoustic parameters of the excitons were determined from the temperature dependence of the PL spectra and were in reasonable agreement with the theoretical calculations. These results can help improve understanding for the application of p-CdxZn1–xTe single crystals in optoelectronic devices.

Point Defects in 4H-SiC Epilayers Introduced by 4.5 MeV Electron Irradiation and their Effect on Power JBS SiC Diode Characteristics

2013 ◽  
Vol 205-206 ◽  
pp. 451-456 ◽  
Author(s):  
Pavel Hazdra ◽  
Vít Záhlava ◽  
Jan Vobecký
Keyword(s):  
Electron Irradiation ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Radiation Defects ◽  
Electrical Parameters ◽  
Power Diodes ◽  
Defect Centers ◽  
Measurement Results ◽  
Transient Spectroscopy ◽  
State Resistance

Electronic properties of radiation damage produced in 4H-SiC by electron irradiation and its effect on electrical parameters of Junction Barrier Schottky (JBS) diodes were investigated. 4H‑SiC N‑epilayers, which formed the low‑doped N-base of JBS power diodes, were irradiated with 4.5 MeV electrons with fluences ranging from 1.5x1014 to 5x1015 cm-2. Radiation defects were then characterized by capacitance deep-level transient spectroscopy and C-V measurement. Results show that electron irradiation introduces two defect centers giving rise to acceptor levels at EC‑0.39 and EC‑0.60 eV. Introduction rate of these centers is 0.24 and 0.65 cm‑1, respectively. These radiation defects have a negligible effect on blocking and dynamic characteristics of irradiated diodes, however, the acceptor character of introduced deep levels and their high introduction rates deteriorate diode’s ON-state resistance already at fluences higher than 1x1015 cm‑2.

scholarly journals Photoluminescence of GaN Grown by Molecular Beam Epitaxy on Freestanding GaN Template

2002 ◽  
Vol 722 ◽  
Author(s):  
M. A. Reshchikov ◽  
F. Yun ◽  
D. Huang ◽  
L. He ◽  
H. Morkoç ◽  
...  
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Broad Band ◽  
Shallow Donor ◽  
Binding Energies ◽  
Main Peak ◽  
Acceptor Pair ◽  
Pl Spectra ◽  
Frequency Plasma ◽  
Donor Acceptor

AbstractWe studied photoluminescence (PL) of GaN layers grown by molecular beam epitaxy on freestanding high-quality GaN templates. The layers with thickness of ∼ 1 νm were grown under Ga-rich conditions using radio-frequency plasma as a nitrogen source. The PL spectra from both the epilayer and the substrate contain a plethora of very sharp peaks related to excitonic transitions. Through the analysis of the excitonic part of the spectra, we have identified two shallow donors with the binding energies of 28.8 and 32.6 meV, attributed to SiGa and ON, respectively. The PL spectra involved also emissions due to shallow donor-acceptor pair transitions with the main peak at 3.26 eV and a broad band peaking at ∼2.5 - 2.6 eV (green band). The green bands in the GaN substrate and GaN overgrown layer have different energy positions invoking the suggestion that they must have their genesis in different defect centers.

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