Excess Carrier Lifetimes in (HgCd)Te Grown by Mocvd Interdiffused Multilayer Process

1994 ◽  
Vol 299 ◽  
Author(s):  
P. Mitra ◽  
T. R. Schimert ◽  
Y. L. Tyan ◽  
A. J. Brouns ◽  
F. C. Case
Keyword(s):  
Millimeter Wave ◽  
Epitaxial Films ◽  
Defect States ◽  
Lifetime Measurements ◽  
Carrier Lifetimes ◽  
As Doping ◽  
Interdiffused Multilayer Process ◽  
Density Of Defect States ◽  
P Type ◽  
Insight Into

AbstractTransient lifetime measurements on p- and n-type Hg1−xCdxTe epitaxial films, grown by the MOCVD-interdiffused multilayer process (IMP) on CdTe and CdZnTe, are reported. Lifetimes have been measured on undoped n-type, vacancy and arsenic doped p-type (HgCd)Te for x-values of 0.20–0.28 over the 25K–300K temperature range. Lifetime characterization has been carried out primarily by non-contact transient millimeter wave reflectance as well as by standard photoconductive decay. It is shown that Auger limited lifetimes are achievable in undoped n-type material. N-type lifetime results are analyzed within the framework of a multilevel Shockley-Read model which provide insight into the nature and density of defect states in the material. In p-type (HgCd)Te, for the same carrier concentration, longer lifetimes are obtained by As-doping than in vacancy doped material.

Excess Carrier Lifetimes in (HgCd)Te Grown by Mocvd Interdiftused Multilayer Process

1993 ◽  
Vol 302 ◽  
Author(s):  
P. Mitra ◽  
T. R. Schimert ◽  
Y. L. Tyan ◽  
A. J. Brouns ◽  
F. C. Case
Keyword(s):  
Millimeter Wave ◽  
Epitaxial Films ◽  
Defect States ◽  
Lifetime Measurements ◽  
Carrier Lifetimes ◽  
As Doping ◽  
Interdiffused Multilayer Process ◽  
Density Of Defect States ◽  
P Type ◽  
Insight Into

ABSTRACTTransient lifetime measurements on p- and n-type Hg1-xCdxTe epitaxial films, grown by the MOCVD-interdiffused multilayer process (IMP) on CdTe and CdZnTe, are reported. Lifetimes have been measured on undoped n-type, vacancy and arsenic doped p-type (HgCd)Te for x-values of 0.20-0.28 over the 25K-300K temperature range. Lifetime characterization has been carried out primarily by non-contact transient millimeter wave reflectance as well as by standard photoconductive decay. It is shown that Auger limited lifetimes are achievable in undoped n-type material. N-type lifetime results are analyzed within the framework of a multilevel Shockley-Read model which provide insight into the nature and density of defect states in the material. In p-type (HgCd)Te, for the same carrier concentration, longer lifetimes are obtained by As-doping than in vacancy doped material.

scholarly journals Control of acceptor doping in MOCVD HgCdTe epilayers

2010 ◽  
Vol 18 (3) ◽  
Author(s):  
P. Madejczyk ◽  
A. Piotrowski ◽  
K. Kłos ◽  
W. Gawron ◽  
J. Rutkowski ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Acceptor Doping ◽  
Carrier Lifetimes ◽  
Wide Range ◽  
Postgrowth Annealing ◽  
Minority Carrier Lifetimes ◽  
Interdiffused Multilayer Process ◽  
Hgcdte Epilayers ◽  
Activation Rates ◽  
P Type

AbstractThe acceptor doping of mercury cadmium telluride (HgCdTe) layers grown by MOCVD are investigated. (111)HgCdTe layers were grown on (100)GaAs substrates at 350°C using horizontal reactor and interdiffused multilayer process (IMP). TDMAAs and AsH3 were alternatively used as effective p-type doping precursors. Incorporation and activation rates of arsenic have been studied. Over a wide range of Hg1−xCdxTe compositions (0.17 < x < 0.4), arsenic doping concentration in the range from 5×1015 cm−3 to 5×1017 cm−3 was obtained without postgrowth annealing. The electrical and chemical properties of epitaxial layers are specified by measurements of SIMS profiles, Hall effect and minority carrier lifetimes. It is confirmed that the Auger-7 mechanism has decisive influence on carrier lifetime in p-type HgCdTe epilayers.

Spectrum of Defect States in Porous Organic Low-k Dielectric Films, Annealed in Argon and Nitrogen

2003 ◽  
Vol 766 ◽  
Author(s):  
V. Ligatchev ◽  
T.K.S. Wong ◽  
T.K. Goh ◽  
Rusli Suzhu Yu
Keyword(s):  
Deep Level ◽  
Dielectric Films ◽  
Silicon Substrates ◽  
Reverse Bias Voltage ◽  
Defect States ◽  
Single Side ◽  
Sandwich Type ◽  
Transient Spectroscopy ◽  
P Type ◽  
Spectrum Deconvolution

AbstractDefect spectrum N(E) of porous organic dielectric (POD) films is studied with capacitance deep-level-transient-spectroscopy (C-DLTS) in the energy range up to 0.7 eV below conduction band bottom Ec. The POD films were prepared by spin coating onto 200mm p-type (1 – 10 Δcm) single-side polished silicon substrates followed by baking at 325°C on a hot plate and curing at 425°C in furnace. The film thickness is in the 5000 – 6000 Å range. The ‘sandwich’ -type NiCr/POD/p-Si/NiCr test structures showed both rectifying DC current-voltage characteristics and linear 1/C2 vs. DC reverse bias voltage. These confirm the applicability of the C-DLTS technique for defect spectrum deconvolution and the n-type conductivity of the studied films. Isochronal annealing (30 min in argon or 60 min in nitrogen) has been performed over the temperature range 300°C - 650°C. The N(E) distribution is only slightly affected by annealing in argon. However, the distribution depends strongly on the annealing temperature in nitrogen ambient. A strong N(E) peak at Ec – E = 0.55 – 0.60 eV is detected in all samples annealed in argon but this peak is practically absent in samples annealed in nitrogen at Ta < 480°C. On the other hand, two new peaks at Ec – E = 0.12 and 0.20 eV appear in the N(E) spectrum of the samples annealed in nitrogen at Ta = 650°C. The different features of the defect spectrum are attributed to different interactions of argon and nitrogen with dangling carbon bonds on the intra-pore surfaces.

Selective Area Deposition of Passivants, Insulators, and Epitaxial Films of II-VI Compound Semiconductors

1989 ◽  
Vol 161 ◽  
Author(s):  
D.L. Dreifus ◽  
Y. Lansari ◽  
J.W. Han ◽  
S. Hwang ◽  
J.W. Cook ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Epitaxial Films ◽  
Semiconductor Surface ◽  
Epitaxial Layers ◽  
Double Crystal ◽  
Surface Areas ◽  
Selective Area ◽  
Lift Off ◽  
P Type ◽  
Area Deposition

ABSTRACTII-VI semiconductor surface passivants, insulators, and epitaxial films have been deposited onto selective surface areas by employing a new masking and lift-off technique. The II-VI layers were grown by either conventional or photoassisted molecular beam epitaxy (MBE). CdTe has been selectively deposited onto HgCdTe epitaxial layers as a surface passivant. Selective-area deposition of ZnS has been used in metal-insulator-semiconductor (MIS) structures. Low resistance ohmic contacts to p-type CdTe:As have also been realized through the use of selectively-placed thin films of the semi-metal HgTe followed by a thermal evaporation of In. Epitaxial layers of HgTe, HgCdTe, and HgTe-CdTe superlattices have also been grown in selective areas on CdZnTe substrates, exhibiting specular morphologies and double-crystal x-ray diffraction rocking curves (DCXD) with full widths at half maximum (FWHMs) as narrow as 140 arcseconds.

On the Temperature Dependence of Resistivity of Polycrystalline Silicon Films

1987 ◽  
Vol 106 ◽  
Author(s):  
Mark S. Rodder ◽  
Dimitri A. Antoniadis
Keyword(s):  
Numerical Calculation ◽  
Polycrystalline Silicon ◽  
Amorphous Region ◽  
Defect States ◽  
Temperature Dependent ◽  
Step Process ◽  
Dependent Potential ◽  
Si Films ◽  
Polycrystalline Silicon Films ◽  
P Type

ABSTRACTIt is shown that the grain boundary (GB) in polycrystalline-silicon (poly-Si) films need not be modeled as a temperature-dependent potential barrier or as an amorphous region to explain the temperature (T) dependence of resistivity (ρ) in p-type poly-Si films at low T. Specifically, we consider that QB defect states allow for the tunneling component of current to occur by a two-step process. Incorporation of the two-step process in a numerical calculation of ρ vs. T results in excellent agreement with available data from 100 K to 300 K.

Molecular insight into extreme copper resistance in the extremophilic archaeon ‘Ferroplasma acidarmanus’ Fer1

Microbiology ◽  
2005 ◽  
Vol 151 (8) ◽  
pp. 2637-2646 ◽  
Author(s):  
Craig Baker-Austin ◽  
Mark Dopson ◽  
Margaret Wexler ◽  
R. Gary Sawers ◽  
Philip L. Bond
Keyword(s):  
Metal Binding ◽  
Stress Proteins ◽  
Mine Drainage ◽  
Copper Resistance ◽  
Genes Encoding ◽  
Ferroplasma Acidarmanus ◽  
Copper Contaminated ◽  
P Type ◽  
Growth Experiments ◽  
Insight Into

‘Ferroplasma acidarmanus’ strain Fer1 is an extremely acidophilic archaeon involved in the genesis of acid mine drainage, and was isolated from copper-contaminated mine solutions at Iron Mountain, CA, USA. Here, the initial proteomic and molecular investigation of Cu2+ resistance in this archaeon is presented. Analysis of Cu2+ toxicity via batch growth experiments and inhibition of oxygen uptake in the presence of ferrous iron demonstrated that Fer1 can grow and respire in the presence of 20 g Cu2+ l−1. The Fer1 copper resistance (cop) loci [originally detected by Ettema, T. J. G., Huynen, M. A., de Vos, W. M. & van der Oost, J. Trends Biochem Sci 28, 170–173 (2003)] include genes encoding a putative transcriptional regulator (copY), a putative metal-binding chaperone (copZ) and a putative copper-transporting P-type ATPase (copB). Transcription analyses demonstrated that copZ and copB are co-transcribed, and transcript levels were increased significantly in response to exposure to high levels of Cu2+, suggesting that the transport system is operating for copper efflux. Proteomic analysis of Fer1 cells exposed to Cu2+ revealed the induction of stress proteins associated with protein folding and DNA repair (including RadA, thermosome and DnaK homologues), suggesting that ‘Ferroplasma acidarmanus’ Fer1 uses multiple mechanisms for resistance to high levels of copper.

scholarly journals Analyzing transport properties of p-type Mg2Si–Mg2Sn solid solutions: optimization of thermoelectric performance and insight into the electronic band structure

2019 ◽  
Vol 7 (3) ◽  
pp. 1045-1054 ◽  
Author(s):  
Hasbuna Kamila ◽  
Prashant Sahu ◽  
Aryan Sankhla ◽  
Mohammad Yasseri ◽  
Hoang-Ngan Pham ◽  
...  
Keyword(s):  
Band Structure ◽  
Transport Properties ◽  
Carrier Concentration ◽  
Solid Solutions ◽  
Figure Of Merit ◽  
Electronic Band Structure ◽  
Thermoelectric Performance ◽  
Electronic Band ◽  
P Type ◽  
Insight Into

Figure of merit zT mapping of p-Mg2Si1−xSnx with respect to carrier concentration.

ITO/a-SiNx:H/a-Si:H Photodiode with Enhanced Photosensitivity and Reduced Leakage Current Using Polycrystalline ITO Deposited at Room Temperature

2000 ◽  
Vol 609 ◽  
Author(s):  
S. Tao ◽  
Q. Ma ◽  
D. Striakhilev ◽  
A. Nathan
Keyword(s):  
Leakage Current ◽  
Dark Current ◽  
Room Temperature ◽  
Dynamic Range ◽  
Transport Model ◽  
Measurement Data ◽  
Mis Structure ◽  
Defect States ◽  
Large Area ◽  
Density Of Defect States

ABSTRACTWe report an ITO/a-SiNx:H/a-Si:H MIS photodiode structure based on room temperature deposition of optically transparent polycrystalline ITO for applications in large area optical and x-ray imaging. The photodiode structure exhibits device characteristics with reduced leakage current and enhanced photosensitivity giving rise to a hundred-fold improvement in dynamic range. This notable improvement in performance is believed to be due to the reduced diffusion of oxygen from the ITO to the a-Si:H layer, and thus reducing the density of defect states inside the a-Si:H layer. The behavior of photo and dark current is consistent with an elaborate transport model for the Schottky barrier. The model agrees reasonably well with measurement data for the dark current and provides a consistent picture in terms of the photo current behavior in the MIS structure, where the insulating layer serves to reduce the oxygen diffusion.

Formation, Structure and Optical Properties of Nanocrystalline BaSi2 Films on Si(111) Substrate

2015 ◽  
Vol 245 ◽  
pp. 42-48 ◽  
Author(s):  
Dmitrii Vladimirovich Fomin ◽  
Victor Leonidovich Dubov ◽  
Konstantin Nickolaevich Galkin ◽  
Dmitrii L'vovich Goroshko ◽  
Andrei Mikhailovich Maslov ◽  
...  
Keyword(s):  
Solid Phase ◽  
Interband Transition ◽  
Grazing Incidence ◽  
Wave Number ◽  
X Ray Diffraction ◽  
Defect States ◽  
Force Microscopy ◽  
Atomic Force ◽  
Density Of Defect States ◽  
Anneal Temperature

BaSi2 thin films were formed on Si (111) substrate by solid-phase epitaxy (SPE) (UHV deposition) using the template technology followed by vacuum annealing at temperatures of 600 °C and 750 °C. After the deposition and annealing barium silicide films were characterized by Auger electron spectroscopy, grazing incidence x-ray diffraction (GIXRD) and atomic-force microscopy (AFM). It was established that the films annealed at T = 600 °C are polycrystalline with the structure of the orthorhombic BaSi2, with grain sizes of 100-200 nm. Higher anneal temperature (T=750 °C) leads to increase of diffraction peak intensity of BaSi2 phase with grain coagulation into 300-400 nm islands. It was confirmed that nanocrystalline BaSi2 films are characterized by a direct fundamental interband transition at 1.3 eV, the second interband transition with an energy of 2.0 eV, own phonon structure with wave number peaks at 112, 119, 146 and 208 cm-1 and a high density of defect states within the band gap, which provide a noticeable subband absorption at energies of 0.8 – 1.1 eV.

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