scholarly journals Parasitic sub-band-gap emission originating from compensating native defects in Si doped AlGaN

2007 ◽  
Vol 91 (12) ◽  
pp. 121110 ◽  
Author(s):  
K. X. Chen ◽  
Q. Dai ◽  
W. Lee ◽  
J. K. Kim ◽  
E. F. Schubert ◽  
...  
Keyword(s):  
Band Gap ◽  
Native Defects ◽  
Si Doped

Band-gap narrowing and potential fluctuation in Si-doped GaN

1999 ◽  
Vol 74 (1) ◽  
pp. 102-104 ◽  
Author(s):  
In-Hwan Lee ◽  
J. J. Lee ◽  
P. Kung ◽  
F. J. Sanchez ◽  
M. Razeghi
Keyword(s):  
Band Gap ◽  
Potential Fluctuation ◽  
Si Doped ◽  
Band Gap Narrowing

scholarly journals Poisonous Vapor Adsorption on Pure and Modified Aluminum Nitride Nanosheet for Environmental Safety: A DFT Exploration

2020 ◽  
Vol 12 (23) ◽  
pp. 10097
Author(s):  
Hongni Zhang ◽  
Wenzheng Du ◽  
Tong Zhao ◽  
Rajeev Ahuja ◽  
Zhao Qian
Keyword(s):  
Band Gap ◽  
Adsorption Energy ◽  
Density Functional ◽  
Theoretical Work ◽  
Environmental Safety ◽  
Atomic Scale ◽  
Atomic Structures ◽  
Vapor Sensing ◽  
Two Dimensional Materials ◽  
Si Doped

Through Density Functional Theory (DFT), we have unveiled the atomic structures, adsorption characteristics and electronic structures of the poisonous and explosive vapor, m-dinitrobenzene (m-DNB), on pure, defective and various doped AlN nanosheets from a physical perspective. It is found that the adsorption energy, band gap change and sensitivity to the vapor are significantly increased through atomic-scale modification of the nanosheet. The AlN monolayer with Al-N divacancy has the largest adsorption energy and has potential to be utilized as adsorption or filtration materials for m-DNB vapor. The Si-doped AlN nanosheet possesses a much larger band gap change (−0.691 eV) than the pure nanosheet (−0.092 eV) after adsorption and has a moderate adsorption energy, which could be candidate material for explosive vapor sensing. This theoretical work is proposed to provide guidance and clue for experimentalists to develop more effective two-dimensional materials for environmental safety and sustainability.

Time resolved spectroscopy of mid-band-gap emissions in Si-doped GaN

1998 ◽  
Vol 189-190 ◽  
pp. 546-550 ◽  
Author(s):  
R Seitz ◽  
C Gaspar ◽  
T Monteiro ◽  
E Pereira ◽  
M Leroux ◽  
...  
Keyword(s):  
Band Gap ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Si Doped

Band-gap renormalization and band filling in Si-doped GaN films studied by photoluminescence spectroscopy

1999 ◽  
Vol 86 (8) ◽  
pp. 4400-4402 ◽  
Author(s):  
M. Yoshikawa ◽  
M. Kunzer ◽  
J. Wagner ◽  
H. Obloh ◽  
P. Schlotter ◽  
...  
Keyword(s):  
Band Gap ◽  
Photoluminescence Spectroscopy ◽  
Band Filling ◽  
Si Doped

Modeling of Chlorine Related Defects and Complexes in ZnMgSe

2001 ◽  
Vol 677 ◽  
Author(s):  
Yaxiang Yang ◽  
Leonid Muratov ◽  
Bernard R. Cooper ◽  
Thomas H. Myers ◽  
John M. Wills
Keyword(s):  
Ab Initio ◽  
Band Gap ◽  
Electron Concentration ◽  
Defect Complex ◽  
Strong Tendency ◽  
Full Potential ◽  
Native Defects ◽  
Lmto Method ◽  
Formation Energies

ABSTRACTWe have used the ab-initio full potential LMTO method to model native defects and chlorine-impurity-related defects in ZnSe and ZnxMg1−xSe. Our results show that there is a strong tendency for formation of a defect complex between a chlorine impurity at the Se site and a vacancy at the neighboring Zn site. The formation energies of this complex and other chlorine related defects decrease in the presence of magnesium. However, the maximum achievable electron concentration in the presence of magnesium is lower because of the increase in the band gap.

Doping Limitation Due to Self-compensation by Native Defects in In-doped Rocksalt CdxZn1-xO

2021 ◽  
Author(s):  
Chun Yuen HO ◽  
Chia Hsiang Li ◽  
Chao Ping Liu ◽  
Zhi-Quan Huang ◽  
Feng-Chuan Chuang ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Band Gap ◽  
Electron Mobility ◽  
Density Functional ◽  
Defect Formation ◽  
Wide Band ◽  
High Electron ◽  
Transparent Conductor ◽  
Full Spectrum ◽  
Native Defects

Abstract CdO-ZnO alloys (CdxZn1-xO) exhibit a transformation from the wurtzite (WZ) to the rocksalt (RS) phase at a CdO composition of ~70% with a drastic change in the band gap and electrical properties. RS-CdxZn1-xO alloys (x>0.7) are particularly interesting for transparent conductor applications due to their wide band gap and high electron mobility. In this work, we synthesized RS-CdxZn1-xO alloys doped with different concentrations of In dopants and evaluated their electrical and optical properties. Experimental results are analyzed in terms of the amphoteric native defect model and compared directly to defect formation energies obtained by hybrid density functional theory (DFT) calculations. A saturation in electron concentration of ~7x1020cm-3 accompanied by a rapid drop in electron mobility is observed for the RS-CdxZn1-xO films with 0.7≤x<1 when the In dopant concentration [In] is larger than 3%. Hybrid DFT calculations confirm that the formation energy of metal vacancy acceptor defects is significantly lower in RS-CdxZn1-xO than in CdO, and hence limits the free carrier concentration. Mobility calculations reveal that due to the strong compensation by native defects, RS-CdxZn1-xO alloys exhibit a compensation ratio of >0.7 for films with x<0.8. As a consequence of the compensation by native defects, in heavily doped RS-CdxZn1-xO carrier-induced band filling effect is limited. Furthermore, the much lower mobility of the RS-CdxZn1-xO alloys also results in a higher resistivity and reduced transmittance in the near infra-red region (λ>1100 nm), making the material not suitable as transparent conductors for full spectrum photovoltaics.

Spontaneous compositional superlattice and band-gap reduction in Si-doped AlxGa1−xN epilayers

2005 ◽  
Vol 87 (19) ◽  
pp. 191906 ◽  
Author(s):  
M. Gao ◽  
Y. Lin ◽  
S. T. Bradley ◽  
S. A. Ringel ◽  
J. Hwang ◽  
...  
Keyword(s):  
Band Gap ◽  
Si Doped

Characterization of Defects in Heavily Si-Doped GaAs by A Monoenergetic Positron Beam

1992 ◽  
Vol 262 ◽  
Author(s):  
A. Uedono ◽  
Y. Ujihira ◽  
L. Wei ◽  
S. Tanigawa
Keyword(s):  
Molecular Beam ◽  
Positron Lifetime ◽  
Positron Beam ◽  
Major Type ◽  
Doppler Broadening ◽  
High Concentration ◽  
Native Defects ◽  
Free Carriers ◽  
Si Doped

ABSTRACTNative defects in Si-doped, Zn-doped and undoped GaAs grown by horizontal Bridgman (HB) method and molecular beam epitaxiy (MBE) were studied by a monoenergetic positron beam. Positron lifetime spectra and Doppler broadening profiles were also measured by using energetic positrons. It was found that monovacancies were usually found in Si-doped HB-GaAs, however, divacancies were created in a specimen with low impurity concentration. For Zn-doped HB-GaAs, interstitial clusters were found to be major type of defects. The high concentration of monovacancies and of divacancies coexist in heavily Si-doped MBE-GaAs. These vacancy-complexes were found to act to reduce the concentration of free carriers.

Photoreflectance study of band-gap renormalization in Si-doped GaN

1998 ◽  
Vol 189-190 ◽  
pp. 687-691 ◽  
Author(s):  
Xiong Zhang ◽  
Soo-Jin Chua ◽  
Wei Liu ◽  
Kok-Boon Chong
Keyword(s):  
Band Gap ◽  
Si Doped
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