Correlation between Room Temperature Photoluminescence and Resistivity in Semiinsulating Silicon Carbide

2006 ◽  
Vol 527-529 ◽  
pp. 717-720 ◽  
Author(s):  
Sashi Kumar Chanda ◽  
Yaroslav Koshka ◽  
Murugesu Yoganathan
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Room Temperature ◽  
Vanadium Content ◽  
Mapping Technique ◽  
Native Defect ◽  
Room Temperature Photoluminescence ◽  
Native Point Defects ◽  
Pl Mapping ◽  
Resistivity Variation

A room temperature PL mapping technique was applied to establish the origin of resistivity variation in PVT-grown 6H SiC substrates. A direct correlation between the native defect-related PL and resistivity was found in undoped (V-free) samples. In vanadium-doped samples with low vanadium content, the resistivity showed a good correlation with the total PL signal consisting of contributions from both vanadium and native point defects. Well-known UD1 and UD3 levels were revealed by low-temperature PL spectroscopy. Some correlation was observed between these low-temperature PL signatures and the resistivity distribution.

Hg1-xCdxTe: Defect Structure Overview

1990 ◽  
Vol 216 ◽  
Author(s):  
M.A. Berding ◽  
A. Sher ◽  
A.-B. Chen
Keyword(s):  
Point Defects ◽  
Defect Structure ◽  
Defect Formation ◽  
Activation Energies ◽  
Mass Action ◽  
Native Defect ◽  
Native Point Defects ◽  
Vacancy Migration ◽  
Formation Energies ◽  
Diffusion Activation

ABSTRACTNative point defects play an important role in HgCdTe. Here we discuss some of the relevant mass action equations, and use recently calculated defect formation energies to discuss relative defect concentrations. In agreement with experiment, the Hg vacancy is found to be the dominant native defect to accommodate excess tellurium. Preliminary estimates find the Hg antisite and the Hg interstitial to be of comparable densities. Our calculated defect formation energies are also consistent with measured diffusion activation energies, assuming the interstitial and vacancy migration energies are small.

EFFECT OF VANADIUM CONTENT ON PHOTOLUMINESCENCE AND MAGNETIC PROPERTIES OF DOPED ZnO THIN FILMS

2010 ◽  
Vol 24 (10) ◽  
pp. 945-951 ◽  
Author(s):  
LIWEI WANG ◽  
ZHENG XU ◽  
SULING ZHAO ◽  
LIFANG LU ◽  
FUJUN ZHANG
Keyword(s):  
Photoluminescence Spectrum ◽  
Room Temperature ◽  
Doping Concentration ◽  
Vanadium Content ◽  
X Ray Diffraction ◽  
Vanadium Concentration ◽  
X Ray ◽  
Room Temperature Photoluminescence ◽  
Room Temperature Photoluminescence Spectrum ◽  
Diffraction Patterns

ZnO : V thin films with different doping concentration (0%, 1.8%, 3.9%, 6.8%, 10%, and 13%) were fabricated by direct current magnetron sputtering. The X-ray diffraction patterns show that the wurzite structure changed with doping concentration. Furthermore, we could not find any vanadium cluster or phase separation in the X-ray diffraction patterns. The photoluminescence of ZnO : V with different vanadium concentration was investigated. The room temperature photoluminescence spectrum indicates that the films have purple band with 370 nm and the bands with 475 and 490 nm. The peak intensity of room temperature photoluminescence spectrum was affected by vanadium contents and its position remained stable. The intensity of band with 370 nm increases with raising the vanadium concentration and then decreases. The hysteresis behavior indicates that films were ferromagnetic at 50 K. Room temperature ferromagnetism was observed for the film with the doping concentration at 6.8%. However, in this case almost no hysteresis is noticeable. The results implied that the doping concentration and crystalline microstructure influence strongly the film's magnetic characteristics. Increasing the vanadium content in the film caused the degradation of the magnetic ordering.

Primary Defects in n-Type Irradiated Germanium: A First-Principles Investigation

2007 ◽  
Vol 131-133 ◽  
pp. 253-258 ◽  
Author(s):  
A. Carvalho ◽  
R. Jones ◽  
C. Janke ◽  
Sven Öberg ◽  
Patrick R. Briddon
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Electron Irradiation ◽  
First Principles ◽  
Low Temperatures ◽  
Damage Evolution ◽  
Room Temperature ◽  
Temperature Electron ◽  
Conductivity Loss

The properties of point defects introduced by low temperature electron irradiation of germanium are investigated by first-principles modeling. Close Frenkel pairs, including the metastable fourfold coordinated defect, are modelled and their stability is discussed. It is found that damage evolution upon annealing below room temperature can be consistently explained with the formation of correlated interstitial-vacancy pairs if the charge-dependent properties of the vacancy and self-interstitial are taken into account. We propose that Frenkel pairs can trap up to two electrons and are responsible for conductivity loss in n-type Ge at low temperatures.

Stability and Relaxation of Point Defects in amorphous silicon

1992 ◽  
Vol 279 ◽  
Author(s):  
Raymond Lutz ◽  
Laurent J. Lewis
Keyword(s):  
Molecular Dynamics ◽  
Low Temperature ◽  
Amorphous Silicon ◽  
Point Defects ◽  
Room Temperature ◽  
Empirical Potential ◽  
The Stability

ABSTRACTWe have used molecular-dynamics to investigate the stability and relaxation of point defects — vacancies and interstitials — in a model of amorphous silicon, with the interactions between atoms described by the Stillinger-Weber empirical potential. The annihila-tion of point defects has been proposed as an important mechanism by which relaxation proceeds in amorphous silicon. Starting with a Wooten-Winer-Weaire model of a-Si, we “manually” create vacancies in the structure by removing a number of randomly-selected four-fold coordinated atoms. The system is then allowed to relax. Our calculations reveal unambiguously that, of a number of vacancies introduced in the model at low temperature, roughly a third are stable; these anneal out upon heating at room temperature. The vacancies seem, in most cases, to consist of a relatively large empty volume bounded by four atoms of which at least one is undercoordinated. Our study of interstitials seems to indicate that they diffuse through a “jump-and-bump” process, eventually annihilating when a large enough, properly coordinated, vacant volume is encountered.

Characterization of interface quality between various low-temperature oxides and Si using room-temperature-photoluminescence and Raman spectroscopy

2013 ◽  
Vol 28 (9) ◽  
pp. 1269-1277 ◽  
Author(s):  
Shiu-Ko Jang Jian ◽  
Chih-Cherng Jeng ◽  
Ting-Chun Wang ◽  
Chih-Mu Huang ◽  
Ying-Lang Wang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Low Temperature ◽  
Room Temperature ◽  
Interface Quality ◽  
Room Temperature Photoluminescence ◽  
Image Position

Abstract

Defect Evolution in Ion Irradiated 6H-SiC Epitaxial Layers

2005 ◽  
Vol 483-485 ◽  
pp. 485-488 ◽  
Author(s):  
Alfonso Ruggiero ◽  
M. Zimbone ◽  
Fabrizio Roccaforte ◽  
Sebania Libertino ◽  
Francesco La Via ◽  
...  
Keyword(s):  
Low Temperature ◽  
Deep Level Transient Spectroscopy ◽  
Room Temperature ◽  
Deep Level ◽  
Room Temperature Photoluminescence ◽  
Temperature Range ◽  
Defect Annealing ◽  
Luminescence Peak ◽  
Transient Spectroscopy ◽  
Dlts Spectra

Deep-Level Transient Spectroscopy and room temperature photoluminescence were used to characterise a 6H-SiC epitaxial layer irradiated with 10 MeV C+ and to follow the defect annealing in the temperature range 300-1400 °C. The intensity of luminescence peak at 423 nm, related to band to band transitions, decreases after irradiation and it is slowly recovered after annealing in the temperature range 1000-1400 °C. The DLTS spectra of low temperature annealed samples show the presence of several overlapping traps, which anneal and evolve at high temperatures. After 1200 °C a main level at Ec-0.43 eV (E1/E2) is detected. The comparison between luminescence and DLTS results indicates that the defect associated with the E1/E2 level is mainly responsible for the luminescence quenching after irradiation.

Native point defects in low‐temperature‐grown GaAs

1995 ◽  
Vol 67 (2) ◽  
pp. 279-281 ◽  
Author(s):  
X. Liu ◽  
A. Prasad ◽  
J. Nishio ◽  
E. R. Weber ◽  
Z. Liliental‐Weber ◽  
...  
Keyword(s):  
Low Temperature ◽  
Point Defects ◽  
Native Point Defects ◽  
Low Temperature Grown Gaas

Room-Temperature Photoluminescence Observation of Stacking Faults in 3C-SiC

2010 ◽  
Vol 645-648 ◽  
pp. 355-358 ◽  
Author(s):  
Rii Hirano ◽  
Michio Tajima ◽  
Kohei M. Itoh
Keyword(s):  
Silicon Carbide ◽  
Optical Properties ◽  
Room Temperature ◽  
Stacking Faults ◽  
Room Temperature Photoluminescence ◽  
Pl Spectra ◽  
Intensity Mapping ◽  
Pl Mapping ◽  
Pl Intensity ◽  
Cubic Silicon Carbide

We investigated the optical properties of stacking faults (SFs) in cubic silicon carbide by photoluminescence (PL) spectroscopy and mapping. The room-temperature PL spectra consisted of a 2.3 eV peak due to nitrogen and two undefined broad peaks at 1.7 eV and 0.95 eV. On the PL intensity mapping for the 2.3 eV peak, SFs appeared as dark lines. SFs which expose carbon atoms (SFC) and silicon atoms (SFSi) on the surface appeared as bright lines and dark lines, respectively, in PL mapping for the 1.7 eV and 0.95 eV peaks. We believe the two undefined peaks are associated with SFC. This technique allows us to detect SFs nondestructively and to distinguish between SFC and SFSi. We further suggest the presence of inhomogeneous stress around SFCs based on the broadening of the 2.3 eV peak.

scholarly journals Room-temperature photoluminescence in erbium-doped deuterated amorphous carbon prepared by low-temperature MO-PECVD

2009 ◽  
Vol 17 (23) ◽  
pp. 21098 ◽  
Author(s):  
Raymond Y. C. Tsai ◽  
Li Qian ◽  
Hossein Alizadeh ◽  
Nazir P. Kherani
Keyword(s):  
Low Temperature ◽  
Amorphous Carbon ◽  
Room Temperature ◽  
Room Temperature Photoluminescence ◽  
Erbium Doped

Nondestructive Analysis of Stacking Faults in 4H-SiC Bulk Wafers by Room-Temperature Photoluminescence Mapping under Deep UV Excitation

2007 ◽  
Vol 556-557 ◽  
pp. 275-278 ◽  
Author(s):  
Norihiro Hoshino ◽  
Michio Tajima ◽  
Toshihiko Hayashi ◽  
Taro Nishiguchi ◽  
Hiroyuki Kinoshita ◽  
...  
Keyword(s):  
Room Temperature ◽  
Stacking Faults ◽  
Surface Region ◽  
Nondestructive Analysis ◽  
Room Temperature Photoluminescence ◽  
Basal Plane Dislocation ◽  
Pl Mapping ◽  
Light Excitation ◽  
Shaped Pattern ◽  
Uv Excitation

The advantage of room-temperature photoluminescence (PL) mapping was demonstrated for nondestructive detection of stacking faults (SFs) in off-oriented 4H-SiC epitaxial and bulk wafers. In mapping of the SF-related emission at 2.9 eV on the wafers, the SFs in the surface region appeared as a bar-shaped pattern with the long side perpendicular to the off-cut direction. The use of 266 nm light excitation is essential to detect the SF pattern in the bulk wafers because of its shallow penetration depth. The dark lines crossing the bar-shaped patterns in the epitaxial wafers are ascribable to the basal plane dislocation located close to the SF-planes.

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