The Effects Of Substitutional Alkaline Metals In Zinc Vacancy Of Zincselenide Single Crystals Grown By The Sublimation Method

1996 ◽  
Vol 442 ◽  
Author(s):  
Kenji Yoshino ◽  
Kouji Maeda ◽  
Atsuhiko Fukuyama ◽  
Yoshito Akashi ◽  
Kiyohisa Imada ◽  
...  
Keyword(s):  
Single Crystals ◽  
Free Exciton ◽  
Energy Shift ◽  
Acceptor Pair ◽  
Deep Acceptor ◽  
Impurity Atoms ◽  
Peak Energy ◽  
Sublimation Method ◽  
Donor Acceptor ◽  
Metal Doped

AbstractThe photoluminescence measurements of alkaline metal doped zincselenide (ZnSe) single crystals were carried out to investigate how the impurity atoms substitute the intrinsic vacancy. Sample are grown by the sublimation method and the Li and Na with the concentrations of 0.1, 0.25 and 0.5 mol% were incorporated simultaneously. In the PL spectra with lower impurity concentrations, bound exciton lines of deep acceptor and donor-acceptor pair (DAP) bands were clearly observed accompanied by a weak free exciton line. Although the bound exciton lines becomes smaller with increasing the impurity concentration, the DAP band remains strong and its peak energy shift to lower energy side with the concentration. The decrease of the bound exciton lines is drastic for Li-doped sample than Na-doped sample. This indicates that Li atoms more easily occupy the Zn vacancies than Na.

Low-temperature luminescence in organic-inorganic lead iodide perovskite single crystals

2021 ◽  
Author(s):  
Irina Vladimirovna Zhevstovskikh ◽  
Nikita Averkiev ◽  
Maksim Sarychev ◽  
Olga Semenova ◽  
Oleg Tereshchenko
Keyword(s):  
Single Crystals ◽  
Thermal Evolution ◽  
Free Exciton ◽  
Orthorhombic Phase ◽  
Lead Iodide ◽  
Acceptor Pair ◽  
Donor And Acceptor ◽  
Donor Acceptor ◽  
Pl Emission ◽  
Methylammonium Lead Iodide

Abstract We present temperature and laser-power dependent photoluminescence (PL) study of methylammonium lead iodide (CH3NH3PbI3) single crystals in the orthorhombic phase. At temperatures below 140 K, we revealed the multi-component PL emission. In addition to a free exciton with an energy of 1.65 eV, we found emission bands with peaks approximately equal to 1.6 eV, 1.52 eV, and 1.48 eV. Analysis of the thermal evolution of the intensities, peak positions, and linewidths of all the PL bands allowed one to determine their origin. We attributed the PL peak with the energy of 1.6 eV to a bound exciton, while the free exciton-bound exciton splitting energy is 50-60 meV. The PL emission with an energy of 1.52 eV can be explained by the donor-acceptor pair (DAP) recombination, where donor and acceptor defects have a depth of about 12 meV and 120 meV, respectively. MA (CH3NH3) interstitials (MA+i ) and lead vacancies (V2-Pb) are the most suitable for the DAP transition to occur in CH3NH3PbI3 crystals. The 1.48 eV PL emission is consistent with the recombination of self-trapped excitons, and interstitial iodine is likely to be an active trap source. We found the variation of the self-trapped depth from 15 meV (at T<80 K) to 53 meV (at T>80 K) with increasing the temperature. Although the multi-component PL emission in CH3NH3PbI3 single crystals appears at low temperatures, defects and excitonic traps that cause this emission can affect the photophysics of hybrid perovskites at higher temperatures.

Formation of Shallow Energy Levels in Mn+ Implanted GaAs with Extremely Low Background Impurity Concentration

1993 ◽  
Vol 316 ◽  
Author(s):  
Honglie Shen ◽  
Yunosuke Makita ◽  
Akimasa Yamada ◽  
Shigeru Niki ◽  
Tsutomu Iida ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Energy Levels ◽  
Energy Shift ◽  
Manganese Concentration ◽  
Acceptor Pair ◽  
Shallow Acceptor ◽  
Background Impurity ◽  
Peak Energy ◽  
Wide Range ◽  
Donor Acceptor

ABSTRACTManganese ions implantation into ultrapure GaAs layers grown by molecular beam epitaxy were investigated by photoluminescence technique systematically in a wide range of manganese concentration up to 1×1020cm-3. Five shallow emission bands denoted by (Mn°, X), “G”, “G' “ “H” and (D, A)2 are formed in the implanted layers in addition to the well known Mn impurity related emission at ~880nm. With increasing manganese concentration to 1×1019cm-3, “G” exhibits no energy shift, suggesting that “G” is different from the behavior of [g-g] emission that is commonly formed in shallow acceptor (such as C) incorporated ultrapure GaAs. (Mn°, X), “G” and “G' “ present no energy shift with increasing excitation intensity, while “H” and (D, A)2 indicate peak energy shift greatly showing typical donor-acceptor pair characteristics. “G” and (Mn°, X) are found to hold similar radiative origin which is different from “G”. Temperature dependence measurement reveals that emission “G” has a thermal activation energy of 5.4meV.

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.

Photoluminescence Of Zincselenide Single Crystals Annealed In Zinc Or Selenium Atmosphere

1994 ◽  
Vol 348 ◽  
Author(s):  
Kenji Yoshino ◽  
Yasushi Matsushima ◽  
Hiroyoshi Kinoshita ◽  
Makoto Hiramatsu
Keyword(s):  
Single Crystals ◽  
Grown Crystal ◽  
Free Exciton ◽  
Bandgap Energy ◽  
Reflection Spectroscopy ◽  
Exciton Line ◽  
Annealing Effects ◽  
Sublimation Method ◽  
Pl Spectrum

ABSTRACTZincselenide single crystals grown by the sublimation method are annealed in Zn or Se atmosphere. The annealing effects are examined by means of photoluminescence (PL) and reflection spectroscopy at 4.2 K. In the PL spectrum for the as-grown crystal, bound exciton lines (I2, I1) are observed. For the Zn-annealed crystal, the free exciton line is clearly observed. For the Se-annealed crystal, peak positions of all lines shift to the higher energies and all lines become sharp, compared with the spectra for the as-grown crystal. It is concluded that Sc-vacancies affect the bandgap energy more than Zn-vacancies do.

scholarly journals Donor-acceptor pair recombination in AgIn5S8 single crystals

1999 ◽  
Vol 85 (6) ◽  
pp. 3198-3201 ◽  
Author(s):  
N. M. Gasanly ◽  
A. Serpengüzel ◽  
A. Aydinli ◽  
O. Gürlü ◽  
I. Yilmaz
Keyword(s):  
Single Crystals ◽  
Acceptor Pair ◽  
Donor Acceptor ◽  
Donor Acceptor Pair

Photoluminescence spectra of undoped and Sm3+-doped BaAl2S4 and BaAl2Se4 single crystals

2001 ◽  
Vol 16 (5) ◽  
pp. 1520-1524 ◽  
Author(s):  
Moon-Seog Jin ◽  
Choong-Il Lee ◽  
Chang-Sun Yoon ◽  
Chang-Dae Kim ◽  
Jae-Mo Goh ◽  
...  
Keyword(s):  
Single Crystals ◽  
Energy Levels ◽  
Photoluminescence Spectra ◽  
Acceptor Pair ◽  
Chemical Transport Reaction ◽  
Ionic Radii ◽  
Transport Reaction ◽  
Broad Emission ◽  
Electron Transitions ◽  
Donor Acceptor

Undoped and Sm3+-doped BaAl2S4 and BaAl2Se4 single crystals were grown by the chemical transport reaction method. The optical energy band gaps of the BaAl2S4 and BaAl2Se4 were found to be 4.10 and 3.47 eV, respectively, at 5 K. In their photoluminescence spectra measured at 5 K, broad emission peaks at 459 and 601 nm appeared in the BaAl2S4 and at 486 and 652 nm in the BaAl2Se4. These emissions are assigned to donor–acceptor pair recombinations. Sharp emission peaks were observed in the Sm3+-doped BaAl2S4 and BaAl2Se4 single crystals at 5 K. Taking into account the ionic radii of the cations and Sm3+, these sharp emission peaks are attributed to the electron transitions between the energy levels of Sm3+ substituting with the Ba site.

Donor-acceptor pair recombination luminescence from Cu2ZnSnS4bulk single crystals

2006 ◽  
Vol 203 (11) ◽  
pp. 2891-2896 ◽  
Author(s):  
K. Tanaka ◽  
Y. Miyamoto ◽  
H. Uchiki ◽  
K. Nakazawa ◽  
H. Araki
Keyword(s):  
Single Crystals ◽  
Acceptor Pair ◽  
Recombination Luminescence ◽  
Donor Acceptor ◽  
Donor Acceptor Pair

Photoluminescence in wurtzite GaN containing carbon

2005 ◽  
Vol 892 ◽  
Author(s):  
Michael A. Reshchikov ◽  
Random H. Patillo ◽  
Kathleen C. Travis
Keyword(s):  
Chemical Vapor ◽  
Growth Conditions ◽  
Shallow Donor ◽  
Clear Correlation ◽  
Acceptor Pair ◽  
Deep Acceptor ◽  
Shallow Acceptor ◽  
Low Intensity ◽  
Sapphire Substrates ◽  
Donor Acceptor

AbstractWe studied photoluminescence (PL) from a set of GaN layers grown on sapphire substrates by metalorganic chemical vapor deposition with the concentration of carbon varied by the growth conditions. One of the remarkable features in these samples is the extremely low intensity of the shallow donor-acceptor pair band. Analysis of the PL data gives the shallow acceptor concentration of less than 1014 cm-3 in most of the C-doped GaN layers. This result shows that C does not form a shallow acceptor, CN, in appreciable concentrations in wurtzite GaN. As for the YL band, there is no clear correlation between its intensity and the degree of C-doping. The question of identification of the deep acceptor responsible for the YL band in undoped and C-doped GaN still remains to be solved.

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