Optical and Electrical Characterizations of AlxGa1−xSb

1987 ◽  
Vol 94 ◽  
Author(s):  
N. Kitamura ◽  
H. Yamamoto ◽  
K. Higuchi ◽  
Y. Maeda ◽  
A. Usami ◽  
...  
Keyword(s):  
Stoichiometric Composition ◽  
Acceptor Level ◽  
Native Defect ◽  
Shallow Acceptor ◽  
Native Defects ◽  
Complex Defect ◽  
Shallow Acceptor Level ◽  
Epma Measurement ◽  
Defect Levels ◽  
Electrical Characterizations

ABSTRACTThe LPE grown AlxGa1−xSb was investigated by means of TEM, a carrier profiler and PL. The TEM image showed the dissociated 60° dislocations and Lomer-Cottrell sessile dislocation formed by the reaction of two dissociated 60° dislocations on different {111} planes. The EPMA measurement showed that Sb concentrations at the dislocation were lower than the stoichiometric composition. The epi-layer grown at 400°C had a relatively uniform carrier concentration of ∼7×1016cm−3. The PL spectra showed five emission peaks in 0≦×≦0.29. One shallow acceptor level and two native defect levels were introduced to interpret these PL emissions. The shallow acceptor level of Ev+∼30meV may be due to the defect of VGaGaSb. The native defects introduce two levels of EΓ1 - ∼90meV and EL1 - ∼160meV. The defect levels may be related to the complex defect of the Sb vacancy.

Properties of the As-related shallow acceptor level in heteroepitaxial ZnSe grown by molecular-beam epitaxy

1993 ◽  
Vol 48 (15) ◽  
pp. 10885-10892 ◽  
Author(s):  
Y. Zhang ◽  
B. J. Skromme ◽  
S. M. Shibli ◽  
M. C. Tamargo
Keyword(s):  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Acceptor Level ◽  
Shallow Acceptor ◽  
Shallow Acceptor Level

Shallow acceptor level in GaAs crystals resulting from Cu diffusion

1964 ◽  
Vol 25 (12) ◽  
pp. 1329-1338 ◽  
Author(s):  
C.S. Fuller ◽  
H.W. Allison ◽  
K.B. Wolfstirn
Keyword(s):  
Acceptor Level ◽  
Shallow Acceptor ◽  
Shallow Acceptor Level

Shallow acceptor level in GaAs crystals resulting from Cu diffusion

1964 ◽  
Vol 2 (8) ◽  
pp. iv
Author(s):  
C.S. Fuller ◽  
H.W. Allison ◽  
K.B. Wolfstirn
Keyword(s):  
Acceptor Level ◽  
Shallow Acceptor ◽  
Shallow Acceptor Level

Identification of Defect Levels in Copper Indium Diselenide (CuInSe2) Thin Films via Photoluminescence Studies

MRS Advances ◽  
2018 ◽  
Vol 3 (52) ◽  
pp. 3135-3141 ◽  
Author(s):  
Niraj Shrestha ◽  
Dhurba R. Sapkota ◽  
Kamala K. Subedi ◽  
Puja Pradhan ◽  
Prakash Koirala ◽  
...  
Keyword(s):  
Thin Film ◽  
Laser Intensity ◽  
Copper Indium Diselenide ◽  
Defect States ◽  
Phonon Replica ◽  
Shallow Acceptor ◽  
Copper Indium ◽  
Defect Levels ◽  
Photoluminescence Studies ◽  
In Cis

Photoluminescence (PL) spectroscopy has been used to study the defect levels in thin film copper indium diselenide (CuInSe2, CIS) which we are developing as the absorber layer for the bottom cell of a monolithically grown perovskite/CuInSe2 tandem solar cell. Temperature and laser power dependent PL measurements of thin film CIS for two different Cu/In ratios (0.66 and 0.80) have been performed. The CIS film with Cu/In = 0.80 shows a prominent donor-to-acceptor peak (DAP) involving a shallow acceptor of binding energy ∼22 meV, with phonon replica at ∼32 meV spacing. In contrast, PL measurement of CIS film for Cu/In = 0.66 taken at 20 K exhibited an asymmetric and broad PL spectrum with peaks at 0.845 eV and 0.787 eV. Laser intensity dependent PL revealed that the observed peaks 0.845 eV and 0.787 eV shift towards higher energy (aka j-shift) at ∼11.7 meV/decade and ∼ 8 meV/decade with increase in laser intensity respectively. The asymmetric and broad spectrum together with large j-shift suggests that the observed peaks at 0.845 eV and 0.787 eV were related to band-to-tail (BT) and band-to-impurity (BI) transition, respectively. Such a band-tail-related transition originates from the potential fluctuation of defect states at low temperature. The appearance of band related transition in CIS film with Cu/In = 0.66 is the indicator of the presence of large number of charged defect states.

Evidence for Different Kinds of Dangling Bond Defects in a-Si:H

1993 ◽  
Vol 297 ◽  
Author(s):  
Minh Tran ◽  
H. Fritzsche ◽  
P. Stradins
Keyword(s):  
Defect Concentration ◽  
Electron Lifetime ◽  
Native Defect ◽  
Dangling Bond ◽  
Native Defects

Comparing the photoconductivity σp of undoped samples with different native defect concentrations we find that light-induced metastable defects decrease the electron lifetime more strongly than the native defects. We discuss the differences between native and metastable dangling bond defects. We find that the constant photocurrent method underestimates the defect concentration in undoped a-Si:H.

scholarly journals Native Umbilical Defect for Laparoscopic Entry

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
Tarek Osama Hegazy ◽  
Mohamed Hassan Ali ◽  
Ahmed Amr Mohsen ◽  
Mahmoud Azhary ◽  
Ahmad Yahia Abdel Dayem
Keyword(s):  
Body Mass Index ◽  
Body Mass ◽  
Native Defect ◽  
Open Technique ◽  
Entry Site ◽  
Native Defects ◽  
Umbilical Incision ◽  
Trocar Insertion ◽  
Laparoscopic Entry ◽  
Direct Trocar Insertion

Background: The presence of defects in native umbilical in adults and its use as laparoscopic first entry site is poorly documented. It would likely be a safer method than the Veress needle and direct trocar insertion. This work aimed to report the prevalence and size of native umbilical defects, and their relationship with gender, age and body mass index. Methods: In 160 consecutive laparoscopic operations, a trans-umbilical incision was made and a defect at its base was looked for. When found, the defect was measured and used as the first port entry site. Relationships of presence of native defects and their sizes in relation to gender, age and BMI were analyzed. Results: The prevalence of a native defect in this series was 90%. Its presence had no relation with gender, age or BMI. Its size, however, positively correlated with age and BMI. No complications were related to the defect’s use for first laparoscopic entry site. Conclusion: A native umbilical defect is present in 90% of adults. Whenever present, it is recommended for use as the first port entry site by an open technique. This method is simple and safe and avoids unnecessarily inducing another defect. Keywords: Laparoscopy, Open technique, Access, Native defect, Umbilical defect

scholarly journals Native defect-assisted enhanced response to CH4 near room temperature by Al0.07Ga0.93N nanowires

2018 ◽  
Vol 20 (27) ◽  
pp. 18391-18399 ◽  
Author(s):  
Santanu Parida ◽  
A. Das ◽  
Arun K. Prasad ◽  
Jay Ghatak ◽  
Sandip Dhara
Keyword(s):  
Room Temperature ◽  
Native Defect ◽  
Native Defects

Enhanced CH4 sensing with sufficient sensitivity of 100 ppm at 50 °C is realized for Al0.07Ga0.93N nanowires by utilizing native defects.

On the Origin of the New Electron Traps Induced By Rapid Thermal Annealing in GaAs Using Capping Proximity Technique.

1988 ◽  
Vol 144 ◽  
Author(s):  
G. Marrakchi ◽  
G. Chaussemy ◽  
A. Laugier ◽  
G. Guillot.
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Native Defect ◽  
Physical Origin ◽  
Electron Traps ◽  
Native Defects ◽  
Growth Method ◽  
Transient Spectroscopy

ABSTRACTRapid Thermal Annealing (RTA) effects on generation or annihilation of deep levels in GaAs have been investigated by Deep Level Transient Spectroscopy (DLTS). Capping proximity technique using three annealing configurations are employed to anneal Liquid Encapsulated Czochralski (LEC) and Bridgman (B) substrates, or Vapor Phase Epitaxy (VPE) and Liquid Phase Epitaxy (LPE) layers. The RTA treatment is performed from 800 to 950°C for two annealing times ( 3 and 10s).The DLTS data show that the evolution of the native defects depends on the GaAs growth method and also the annealing configuration. We observe the appearance of two new electron traps named RL1 and RL2 induced by the RTA process which depend on the kind of substrate: RL1 and RL2 are created in LEC material while only RL1 is detected in B material. A general comparison of our results with others reported in the literature show that these new electron traps are related to the change of stoichiometry at the GaAs surface and also depend on the existence of specific native defects in the starting GaAs material. It is proposed that the creation of RL1 is related to the EL6 native defect and discuss a possible physical origin for this level. We also propose that RL2 and EL5 originate from the same defect and suggest the divacancy VGaVAs as a possible origin for this trap.

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