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.

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.

CuIn1-xGaxSe2 Thin Films Prepared by Co-Evaporation Technique

2013 ◽  
Vol 827 ◽  
pp. 12-15
Author(s):  
Ya Fen Wu ◽  
Jiunn Chyi Lee
Keyword(s):  
Thin Films ◽  
Energy Levels ◽  
Luminescence Spectra ◽  
Photoluminescence Spectra ◽  
Acceptor Pair ◽  
Shallow Acceptor ◽  
Donor Acceptor ◽  
Evaporation Technique ◽  
Donor Acceptor Pair ◽  
Gallium Content

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.

scholarly journals Optical Activation Behavior of Ion Implanted Acceptor Species in GaN

2000 ◽  
Vol 5 (S1) ◽  
pp. 507-513 ◽  
Author(s):  
B.J. Skromme ◽  
G.L. Martinez
Keyword(s):  
Variable Temperature ◽  
Spectroscopic Properties ◽  
Acceptor Pair ◽  
High Quality ◽  
Shallow Acceptor ◽  
Implantation Damage ◽  
Donor Acceptor ◽  
Optical Activation ◽  
Optical Binding ◽  
Dose Dependent

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.

scholarly journals Studies on Carbon as Alternative P-Type Dopant for Gallium Nitride

1999 ◽  
Vol 4 (S1) ◽  
pp. 526-531 ◽  
Author(s):  
U. Birkle ◽  
M. Fehrer ◽  
V. Kirchner ◽  
S. Einfeldt ◽  
D. Hommel ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Atomic Layer ◽  
Typical Feature ◽  
Acceptor Pair ◽  
Carbon Doped ◽  
Order Of Magnitude ◽  
Donor Acceptor ◽  
Donor Acceptor Pair ◽  
P Type ◽  
Carbon Concentrations

GaN layers were grown by molecular beam epitaxy and doped with carbon of nominal concentrations ranging from 1016 cm−3 to 1020 cm−3. The incorporation of carbon leads to a reduction of the background electron concentration by one order of magnitude but the material remains n-type. For high carbon concentrations a re-increase of the carrier concentration is observed which is related to selfcompensation. Investigations of the donor-acceptor-pair luminescence show that doping with carbon is accompanied by the generation of a new donor exhibiting a thermal activation energy of about 55 meV. Layers grown by atomic layer epitaxy are marked by an increased intensity of the donor-acceptor-pair band luminescence which is attributed to the enforced incorporation of carbon onto the nitrogen sublattice. The yellow luminescence is found to be a typical feature of all carbon doped layers in contrast to nominally undoped samples.

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.

scholarly journals Free to Bound Recombination and Screening Effects in CdS

1974 ◽  
Vol 52 (8) ◽  
pp. 721-727 ◽  
Author(s):  
R. M. Egloff ◽  
K. Colbow
Keyword(s):  
Binding Energy ◽  
Broad Band ◽  
Energy Shift ◽  
Excitation Intensity ◽  
Free Carrier ◽  
Hot Electrons ◽  
Acceptor Interaction ◽  
Shallow Acceptor ◽  
Free Carriers ◽  
Donor Acceptor

The luminescence spectrum of CdS consists of a number of sharp lines from 2.43 eV to the band edge at 2.58 eV and a number of broad bands below 2.43 eV. The highest energy broad band is due to a free electron recombining with a hole bound at a shallow acceptor (free to bound). The dependence of the free to bound peak of energy on temperature and excitation intensity is investigated in the interval 4.2–80 K. Increasing the excitation intensity results in a shift to higher energy. This is interpreted in terms of free carrier screening which reduces the binding energy of the acceptor. An energy shift due to the recombination of hot electrons is also considered. An often neglected donor–acceptor interaction term is discussed and found to be significant for an accurate measurement of the acceptor binding energy. Experimental observations suggest that screening of excitons due to free carriers is ineffective.

Studies on Carbon as Alternative P-Type Dopant for Gallium Nitride

1998 ◽  
Vol 537 ◽  
Author(s):  
U. Birkle ◽  
M. Fehrer ◽  
V. Kirchner ◽  
S. Einfeldt ◽  
D. Hommel ◽  
...  
Keyword(s):  
Thermal Activation ◽  
Atomic Layer ◽  
Typical Feature ◽  
Acceptor Pair ◽  
Carbon Doped ◽  
Order Of Magnitude ◽  
Donor Acceptor ◽  
Donor Acceptor Pair ◽  
P Type ◽  
Carbon Concentrations

AbstractGaN layers were grown by molecular beam epitaxy and doped with carbon of nominal concentrations ranging from 1016 cm-1 to 10 20 cm-1. The incorporation of carbon leads to a reduction of the background electron concentration by one order of magnitude but the material remains n-type. For high carbon concentrations a re-increase of the carrier concentration is observed which is related to selfcompensation. Investigations of the donor-acceptor-pair luminescence show that doping with carbon is accompanied by the generation of a new donor exhibiting a thermal activation energy of about 55 meV. Layers grown by atomic layer epitaxy are marked by an increased intensity of the donor-acceptor-pair band luminescence which is attributed to the enforced incorporation of carbon onto the nitrogen sublattice. The yellow luminescence is found to be a typical feature of all carbon doped layers in contrast to nominally undoped samples.

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.

Thermal Activation of Beryllium in GaN Grown by RF-Plasma Molecular Beam Epitaxy

2003 ◽  
Vol 798 ◽  
Author(s):  
B. L. VanMil ◽  
Kyoungnae Lee ◽  
Lijun Wang ◽  
N. C. Giles ◽  
T. H. Myers
Keyword(s):  
Molecular Beam Epitaxy ◽  
Thermal Activation ◽  
Molecular Beam ◽  
Rf Plasma ◽  
Acceptor Pair ◽  
Pure Nitrogen ◽  
Donor Acceptor ◽  
Hydrogen Mixtures ◽  
Donor Acceptor Pair ◽  
Polar Mechanism

ABSTRACTDifferences in the optical activity of Be in GaN epilayers grown on different surface polarities by rf-plasma molecular beam epitaxy are investigated. Nitrogen-polar GaN doped with Be exhibits a significantly higher intensity of donor-acceptor pair (DAP) photoluminescence (PL) than similarly doped Ga-polar GaN, indicating the Be is incorporating at microscopically different sites, or possibly is forming different compensating complexes. Highly Be-doped Ga-polar GaN apparently forms isolated polarity-inverted regions which then incorporate Be via the N-polar mechanism resulting in the DAP PL. High temperature annealing of the Ga-polar layers both under nitrogen/hydrogen mixtures and under pure nitrogen atmospheres activates the DAP PL.

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