Photoluminescence Study of Damage Introduced in GaN by Ar- and Kr-Plasmas Etching

2011 ◽  
Vol 1396 ◽  
Author(s):  
Yoshitaka Nakano ◽  
Retsuo Kawakami ◽  
Masahito Niibe ◽  
Atsushi Takeichi ◽  
Takeshi Inaoka ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Luminescence Band ◽  
Shallow Donor ◽  
Acceptor Pair ◽  
Near Surface ◽  
Photoluminescence Study ◽  
Damage Characteristics ◽  
Donor Acceptor ◽  
Donor Acceptor Pair ◽  
Blue Luminescence Band

ABSTRACTWe investigated, by employing a photoluminescence technique, the etching damage introduced in near-surface regions of GaN by Ar and Kr plasmas and clarified the differences between the damage characteristics of these regions for the two plasma etching cases. For Ar plasma, the shallow donor-acceptor pair emission at ~3.28 eV was significantly weakened; additionally, a broad blue luminescence band arose at approximately ~3.0 eV. In contrast, for Kr plasma under high gas pressure, we found the recovery of the damage to the same level as the as-grown crystallinity. These differences in the damage characteristics for the two plasma etching cases probably depend upon which atom (N or Ga) is preferentially etched in these cases.

Fabrication and Luminescence Properties of Monoclinic Gallium Oxide (β-Ga2O3) Nanostructures

2006 ◽  
Vol 951 ◽  
Author(s):  
Aurangzeb Khan ◽  
Wojciech M. Jadwisienczak ◽  
Henryk J. Lozykowski ◽  
Martin E. Kordesch
Keyword(s):  
Gallium Oxide ◽  
Luminescence Band ◽  
Thermal Evaporation ◽  
Acceptor Pair ◽  
Evaporation And Condensation ◽  
Argon Flow ◽  
Exciton Recombination ◽  
Donor Acceptor ◽  
Donor Acceptor Pair ◽  
Micro Pillars

ABSTRACTβ-Ga2O3 nanostructures including nanowires, nanorods, nano and micro-pillars, nanosheets and nanobelts were successfully fabricated by simple and efficient thermal evaporation and condensation technique under argon flow.. The structures have been investigated by the electron microscope, XRD and EDX techniques and shown that nanostructures are predominatly β-Ga2O3 without other crystallographic phases. Cathodouminescence of as-grown nanostructures was investigated in the 10-300 K temperature range and exhibit luminescence band centered at 485 nm at 300 K due to donor-acceptor pair recombination. A new luminescence band centered at 387 nm developes at temperature below 150 K due to self-trapped exciton recombination.

Deep Donor-Acceptor Pair Luminescence in Codoped GaN

2002 ◽  
Vol 743 ◽  
Author(s):  
Bing Han ◽  
Joel M. Gregie ◽  
Melville P. Ulmer ◽  
Bruce W. Wessels
Keyword(s):  
Luminescence Band ◽  
Room Temperature ◽  
Deep Level ◽  
Excitation Density ◽  
Acceptor Pair ◽  
Deep Donor ◽  
Donor Acceptor ◽  
Donor Acceptor Pair ◽  
Increasing Temperature ◽  
Luminescent Behavior

ABSTRACTDeep level defects formed in p-type GaN:Mg codoped with shallow donors have been investigated by photoluminescence (PL) spectroscopy. A donor-acceptor pair (DAP) luminescence band peaked at 2.45 eV dominates the room temperature PL spectrum in heavily codoped epilayers. A superlinear dependence of PL intensity on excitation density is observed for this band, with an exponent of 1.4∼1.7. The intensity of this band increases with increasing temperature with a maximum at 264K. To explain the luminescent behavior a DAP model was developed whereby the recombination involves a deep donor and shallow Mg acceptor. The deep donor is tentatively attributed to a DX center.

High quantum efficiency of photoluminescence in GaN and ZnO

2005 ◽  
Vol 892 ◽  
Author(s):  
Michael A. Reshchikov ◽  
Xing Gu ◽  
Bill Nemeth ◽  
Jeff Nause ◽  
Hadis Morkoç
Keyword(s):  
Quantum Efficiency ◽  
Molecular Beam ◽  
Shallow Donor ◽  
Nonradiative Recombination ◽  
Acceptor Pair ◽  
High Quantum Efficiency ◽  
Donor Acceptor ◽  
Si Doped ◽  
Donor Acceptor Pair ◽  
Zno Crystal

AbstractThe quantum efficiency (QE) of photoluminescence (PL) has been estimated in GaN and ZnO samples. A Si-doped GaN layer grown by molecular beam epitaxy (MBE) exhibited the highest QE of about 90% at low temperatures. Recombination via the shallow donor-acceptor pair transitions dominated in this sample. In contrast, a bulk ZnO crystal with the QE of PL of about 85% contained almost no defect- or impurity-related PL signatures besides the emission attributed to free and bound excitons. The sources of radiative and nonradiative recombination in GaN and ZnO are discussed.

Structural and Optical Characterization of CuxGaySe2Thin Films under Excitation with Above and Below Band Gap Laser Light

2002 ◽  
Vol 730 ◽  
Author(s):  
C. Xue ◽  
D. Papadimitriou ◽  
Y.S. Raptis ◽  
T. Riedle ◽  
N. Esser ◽  
...  
Keyword(s):  
Band Gap ◽  
Raman Spectra ◽  
Laser Light ◽  
Film Surface ◽  
Shallow Donor ◽  
Acceptor Pair ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Donor Acceptor Pair

AbstractCuxGaySe2MOCVD and PVD grown films were structurally and optically characterized by Raman, Micro-Raman and photoluminescence spectroscopy. Defect related photoluminescence excitation with wavelengths varying across the material band gap reveals: a) in Cu-rich CuGaSe2films, three band edge splitting due to the spin-orbit interaction and the crystal field, and donor-acceptor pair recombination between a shallow donor and two different acceptor levels, and b) in Ga-rich CuGaSe2films, donor-acceptor pair transitions between quasi-continua of donor and acceptor levels related to potential fluctuations. Raman spectra of CuxGaySe2films, excited by laser light near and below the material band gap, show intense modes at 197cm-1, 187cm-1, and 277cm-1, which can be used as indicators of crystallinity and Ga-content of the films. Polarization- and angular- dependent micro-Raman spectra of MOCVD CuGaSe2indicate that CuxSey-crystallites, dispersed on the surface of Cu-rich films, are grown oriented with their c-axis perpendicular to the film surface.

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.

The role of potential fluctuations in continuous-wave donor–acceptor pair luminescence of heavily doped materials

1999 ◽  
Vol 75 (9) ◽  
pp. 1243-1245 ◽  
Author(s):  
I. Kuskovsky ◽  
D. Li ◽  
G. F. Neumark ◽  
V. N. Bondarev ◽  
P. V. Pikhitsa
Keyword(s):  
Continuous Wave ◽  
Acceptor Pair ◽  
Potential Fluctuations ◽  
Donor Acceptor ◽  
Heavily Doped ◽  
Donor Acceptor Pair ◽  
Doped Materials
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