Spatial distribution of deep level defects in crack-free AlGaN grown on GaN with a high-temperature AlN interlayer

2006 ◽  
Vol 100 (12) ◽  
pp. 123101 ◽  
Author(s):  
Q. Sun ◽  
H. Wang ◽  
D. S. Jiang ◽  
R. Q. Jin ◽  
Y. Huang ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
High Temperature ◽  
Deep Level

Deep Donor and Acceptor Levels Induced by High Temperature and long time Annealing in LEC Gallium Arsenide

1991 ◽  
Vol 240 ◽  
Author(s):  
G. Marrakchi ◽  
A. Kalboussi ◽  
G. Guillot ◽  
M. Ben Salem ◽  
H. Maaref ◽  
...  
Keyword(s):  
High Temperature ◽  
Cold Water ◽  
Deep Level ◽  
Electron Trap ◽  
Single Donor ◽  
Long Duration ◽  
Donor And Acceptor ◽  
Deep Donor ◽  
Long Time ◽  
Lec Gaas

ABSTRACTThe effects of high temperature isothermal annealing on the electrical properties of donor and acceptor defects in n-type LEC GaAs are investigated. The annealing experiments are performed under As-rich atmosphere at 1000°C for 1–4 and 16 hours followed by a very quick quenching into cold water of the quartz ampoules containing the samples. The donor and acceptor levels are detected respectively by standard (DLTS) and optical (ODLTS) deep level spectroscopy. DLTS results show the presence of one single donor level present in unannealed and annealed samples at Ec - 0.79eV which is identified as the well known electron trap EL2 Only the sample annealed for 16 hs exhibits the presence of a new electron trap named TAI at Ec - 0.32eV. The appearance of TAI is correlated in one hand with the evolution of EL2 concentration and in the other hand to the effect of long duration (16 hs) of the treatment. For acceptor levels, two hole traps HT1 and HT2 are detected respectively at EV + 0.18 eV and EV+ 0.28 eV. HT1 is detected only in samples annealed for 4 and 16 hs and HT2 is detected in all studied samples. Photoluminescence (PL) measurements show the presence of the 1.44 eV band corresponding to gallium antisite GaAs defect. This band observed in unannealed and annealed samples shows that GaAs remains stable even after thermal annealing at lOOO°C for 16 hs and it is correlated with the presence of HT2.

Deep level studies in high-temperature annealed silicon wafers for layer transfer in thin-film solar cells

2012 ◽  
Vol 209 (10) ◽  
pp. 1857-1860
Author(s):  
Eddy Simoen ◽  
Valerie Depauw ◽  
Ivan Gordon ◽  
Jef Poortmans
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
High Temperature ◽  
Deep Level ◽  
Silicon Wafers ◽  
Thin Film Solar Cells ◽  
Layer Transfer

Investigation of carrier compensation traps in n−-GaN drift layer by high-temperature deep-level transient spectroscopy

2020 ◽  
Vol 117 (11) ◽  
pp. 112103
Author(s):  
Huayang Huang ◽  
Xuelin Yang ◽  
Shan Wu ◽  
Jianfei Shen ◽  
Xiaoguang He ◽  
...  
Keyword(s):  
High Temperature ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Transient Spectroscopy ◽  
Drift Layer

scholarly journals Experimental maturation of feathers: implications for reconstructions of fossil feather colour

2013 ◽  
Vol 9 (3) ◽  
pp. 20130184 ◽  
Author(s):  
Maria E. McNamara ◽  
Derek E. G. Briggs ◽  
Patrick J. Orr ◽  
Daniel J. Field ◽  
Zhengrong Wang
Keyword(s):  
High Pressure ◽  
Spatial Distribution ◽  
High Temperature ◽  
Plumage Coloration ◽  
Complete Degradation ◽  
Ordered Arrays ◽  
Visual Evidence ◽  
High Pressure High Temperature

Fossil feathers often preserve evidence of melanosomes—micrometre-scale melanin-bearing organelles that have been used to infer original colours and patterns of the plumage of dinosaurs. Such reconstructions acknowledge that evidence from other colour-producing mechanisms is presently elusive and assume that melanosome geometry is not altered during fossilization. Here, we provide the first test of this assumption, using high pressure–high temperature autoclave experiments on modern feathers to simulate the effects of burial on feather colour. Our experiments show that melanosomes are retained despite loss of visual evidence of colour and complete degradation of other colour-producing structures (e.g. quasi-ordered arrays in barbs and the keratin cortex in barbules). Significantly, however, melanosome geometry and spatial distribution are altered by the effects of pressure and temperature. These results demonstrate that reconstructions of original plumage coloration in fossils where preserved features of melanosomes are affected by diagenesis should be treated with caution. Reconstructions of fossil feather colour require assessment of the extent of preservation of various colour-producing mechanisms, and, critically, the extent of alteration of melanosome geometry.

Process-Induced Defects in High-Purity GaAs

1982 ◽  
Vol 14 ◽  
Author(s):  
P. H. Campbell ◽  
O. Aina ◽  
B. J. Baliga ◽  
R. Ehle
Keyword(s):  
High Temperature ◽  
High Purity ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Deep Levels ◽  
Schottky Contacts ◽  
High Temperature Annealing ◽  
Order Of Magnitude ◽  
Transient Spectroscopy ◽  
Induced Defects

ABSTRACTHigh temperature annealing of Si 3 N4 and SiO2 capped high purity LPE GaAs is shown to result in a reduction in the surface carrier concentration by about an order of magnitude. Au Schottky contacts made on the annealed samples were found to have severely degraded breakdown characteristics. Using deep level transient spectroscopy, deep levels at EC–.58eV, EC–.785eV were detected in the SiO2, capped samples and EC–.62eV, EC–.728eV in the Si3N4 capped Samples while none was detected in the unannealed samples.The electrical degradations are explained in terms of compensation mechanisns and depletion layer recombination-generation currents due to the deep levels.

scholarly journals Spatial distribution and seasonal dynamics of non-biting moth flies (Diptera, Psychodidae) in confound conditions of a stable

2020 ◽  
Vol 89 (4 - Ahead of print) ◽  
pp. 190-199
Author(s):  
Marek Semelbauer ◽  
Jozef Oboňa ◽  
Marek Barta ◽  
Barbara Mangová ◽  
Milan Kozánek
Keyword(s):  
Organic Matter ◽  
Spatial Distribution ◽  
High Temperature ◽  
Seasonal Dynamics ◽  
Life Style ◽  
Flight Period ◽  
Internal Wall ◽  
Biting Midges ◽  
Malaise Traps

Many small Diptera adopted at some level endophilic life style, including man-made buildings. Stables create a specific type of microhabitat, which provides shady and relatively humid conditions in combination with excess of organic matter. Unlike the parasites (mosquitos, biting midges, etc.), the commensal fauna of stables is poorly studied. Moth flies (Psychodidae) were collected in cow stable located in Šenkvice, SW Slovakia. Special traps (derived from Malaise traps) were installed along the stable internal wall and in three different heights. In total, we recorded 6325 moth flies belonging to 8 species. The flight period lasted from spring to autumn. Seasonal dynamics was strongly influenced by rainfall and mean week temperature, e.g. high temperature in mid-summer caused drop in moth flies captures. The moth flies clearly preferred the ground and moderately preferred the interior of stable.

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