Annealing Behavior of Deep Trap Level in p-GaTe

AbstractWe report on the optical properties of defects introduced in epitaxial 4H-SiC by 2 MeV protons using photoluminescence spectroscopy. The near band edge characteristics of nitrogen-doped n-type 4H-SiC are present in the optical spectrum of the as-grown samples. Following a proton irradiation, the material is altered and the luminescence of the shallow centers is attenuated almost entirely with the emergence of deeper shallow traps at energies greater than 300 meV below the conduction band. Subsequent hightemperature thermal annealing of the material results in an increase in the emission spectrum at both the near band edge region (Eg = 3.25 eV) and between 2.65 and 2.95 eV. Recovery of the characteristic nitrogen-related peaks at the near band edge following high-temperature annealing is identified, but is not complete even at 1500 °C. In the deep trap region below 2.95 eV, activation of trap centers with annealing results in a sharp increase in the signal intensity of an irradiation-induced defect trap (2.90 eV) as well as the associated phonon replicas. Based on previous ion-implantation and other radiation studies in 4H-SiC, the emergence of the 2.90 eV defect complex and associated phonon replicas after high temperature anneal is the well known D1 photoluminescence. The observed lines in the D1 spectrum are due to exciton recombination at isoelectronic defect centers.

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Hydrogen Diffusion Mechanism in Amorphous Silicon From D Tracer Diffusion: Theory and Experiment

MRS Proceedings ◽

10.1557/proc-297-279 ◽

1993 ◽

Vol 297 ◽

Cited By ~ 5

Author(s):

Howard M. Branz ◽

Sally Asher ◽

Brent P. Nelson ◽

Mathieu Kemp

Keyword(s):

Hydrogen Diffusion ◽

Diffusion Mechanism ◽

Effective Diffusion ◽

Early Time ◽

Deep Trap ◽

Tracer Diffusion ◽

Release Time ◽

Decay Length ◽

Trap Level ◽

The Mean

We compare experimental diffusion studies to the results of a theoretical study of diffusion controlled by a single deep trap level. Analytic solutions for the D profiles after annealing depend on the characteristic H release time, τ, from the deep trap. At times much shorter than τ, the D profile develops exponential wings whose decay length is the mean D displacement between trapping events. The long-time D profile is a solution to the ideal diffusion equation, but with an effective diffusion coefficient that can be calculated from features of the early-time profiles. New experimental data establish the validity of the model at a range of anneal times and temperatures. We also find that the mean displacement of free H before retrapping decreases with both increased illumination and increasing anneal temperature.

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Profiling the Deep Trap Level in the Semiconductor Heterostructures by Small-Pulse Deep Level Transient Spectroscopy

MRS Proceedings ◽

10.1557/proc-338-195 ◽

1994 ◽

Vol 338 ◽

Author(s):

Zhang Rong ◽

Yang Kai ◽

Qing Guoyi ◽

Shi Yi ◽

Gu Shulin ◽

...

Keyword(s):

Deep Level ◽

Deep Trap ◽

Good Method ◽

Deep Levels ◽

Semiconductor Heterostructures ◽

Trap Level ◽

Narrow Gap ◽

Transient Spectroscopy ◽

First Time ◽

Doping Condition

ABSTRACTIn this paper we report for the first time theoretical and experimental study on smallpulse DLTS measurements of deep levels in semiconductor heterostructures. A theoretical model has been developed on the basis of the Schodinger and Poisson's electrostatic equation. Distribution of charge density in the superlattice has been considered, especially transferred charges in the “narrow gap” sublayers. The calculated results indicate that tinder the 1017/cm3 doping condition, a 30mV small pulse corresponds to a 2nm “sampling space window”, it is enough to detect special signal of deep levels in each sublayer in the semiconductor heterostructures. A SiGe/Si sample has been measured by the small-pulse DLTS. The experimental results agree well with the theoretical prediction and show that the small-pulse DLTS is a good method to study deep levels in the semiconductor heterostructures.

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Novel Co‐Doped Y 2 GeO 5 :Pr 3+ ,Tb 3+ : Deep Trap Level Formation and Analog Binary Optical Storage with Submicron Information Points

Advanced Optical Materials ◽

10.1002/adom.202002090 ◽

2021 ◽

pp. 2002090

Author(s):

Mingxue Deng ◽

Qian Liu ◽

Ying Zhang ◽

Caiyan Wang ◽

Xinjun Guo ◽

...

Keyword(s):

Deep Trap ◽

Optical Storage ◽

Trap Level ◽

Co Doped

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Visible light driven photocatalytic activity of Fe-doped ZnO nanocrystals

Functional Materials Letters ◽

10.1142/s1793604717500023 ◽

2017 ◽

Vol 10 (02) ◽

pp. 1750002 ◽

Cited By ~ 7

Author(s):

Bao-Gai Zhai ◽

Long Yang ◽

Qing-Lan Ma ◽

Yuan Ming Huang

Keyword(s):

Photocatalytic Activity ◽

Visible Light ◽

Density Functional ◽

Diffuse Reflectance Spectroscopy ◽

Deep Trap ◽

Precipitation Method ◽

Trap Level ◽

Zno Nanocrystals ◽

Visible Light Driven ◽

Doped Zno

Fe-doped ZnO nanocrystals at the level of 8[Formula: see text]mol% were synthesized via the co-precipitation method and then characterized by transmission electron microscopy, X-ray diffraction, diffuse reflectance spectroscopy and UV–Vis absorption spectroscopy. Strong absorptions with its peak at around 500[Formula: see text]nm were recorded in the range of 400–600[Formula: see text]nm for Fe-doped ZnO nanocrystals. Visible-light driven photocatalytic activity of Fe-doped ZnO nanocrystals was demonstrated via the photocatalytic degradation of methyl orange dye. Density functional calculations show that Fe dopant can generate a deep trap level at Ev [Formula: see text] 1.01[Formula: see text]eV in the bandgap of ZnO, which is believed to be responsible for the visible light responsive photocatalytic activity of Fe-doped ZnO.

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Observations in Changes of Electrical Properties in Thermally Neutron-Exposed Boron-Doped Silicon Semiconductors

Journal of Nuclear Engineering and Radiation Science ◽

10.1115/1.4029961 ◽

2015 ◽

Vol 1 (3) ◽

Author(s):

Hector E. Medina ◽

Brian Hinderliter

Keyword(s):

Electrical Properties ◽

Boron Concentration ◽

National Laboratory ◽

Radiation Detection ◽

Neutron Radiation ◽

Deep Trap ◽

Trap Level ◽

Boron Doped ◽

Before And After ◽

Electronic Parameters

Boron-doped resistors and transistors were developed using various levels of boron concentration. These were exposed to a thermal neutron flux of about 2×108 s−1 cm−2 at various fluences, at Los Alamos National Laboratory. Characterization of some electrical properties was carried out before and after irradiation. The reaction, 10B+n→Li+α, and others, caused by neutron irradiation, introduced impurities in the silicon lattice, thus producing measurable differences in electronic parameters. The results show that for irradiated resistors possessing very low values of boron concentration (≈1014 cm−3), there is a significant reduction (i.e., orders of magnitude) in resistivity, for the higher fluences studied (2×1011–1012 cm−2). This trend is not seen for high values of boron concentration (≈1021 cm−3), nor for the low-boron-concentration specimens exposed to a lower fluence. These observations appear to be in accordance with the deep-trap level behavior, and, though requiring further study, they seem to be promising for the potential application on neutron radiation detection. Additionally, there was no observation of significant changes in other electronic parameters, such as threshold voltage or trans-conductance, for the transistors exposed and tested.

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Two-stage self-seeding method for preparation of single crystals of poly(phenylene sulfide)

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100153816 ◽

1989 ◽

Vol 47 ◽

pp. 368-369

Author(s):

Sengshiu Chung ◽

Peggy Cebe

Keyword(s):

Single Crystals ◽

High Performance ◽

Dilute Solution ◽

Two Stage ◽

Annealing Behavior ◽

High Performance Polymers ◽

Seeding Method ◽

Phenylene Sulfide

We are studying the crystallization and annealing behavior of high performance polymers, like poly(p-pheny1ene sulfide) PPS, and poly-(etheretherketone), PEEK. Our purpose is to determine whether PPS, which is similar in many ways to PEEK, undergoes reorganization during annealing. In an effort to address the issue of reorganization, we are studying solution grown single crystals of PPS as model materials.Observation of solution grown PPS crystals has been reported. Even from dilute solution, embrionic spherulites and aggregates were formed. We observe that these morphologies result when solutions containing uncrystallized polymer are cooled. To obtain samples of uniform single crystals, we have used two-stage self seeding and solution replacement techniques.

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Metastable Defects in the Amorphous Silicon-Germanium Alloys

MRS Proceedings ◽

10.1557/proc-762-a2.1 ◽

2003 ◽

Vol 762 ◽

Cited By ~ 1

Author(s):

J. David Cohen

Keyword(s):

Amorphous Silicon ◽

Silicon Germanium ◽

Dangling Bonds ◽

Annealing Behavior ◽

Fundamental Properties ◽

Silicon Materials ◽

Salient Features ◽

The Individual ◽

Amorphous Silicon Germanium ◽

Silicon Germanium Alloys

AbstractThis paper first briefly reviews a few of the early studies that established some of the salient features of light-induced degradation in a-Si,Ge:H. In particular, I discuss the fact that both Si and Ge metastable dangling bonds are involved. I then review some of the recent studies carried out by members of my laboratory concerning the details of degradation in the low Ge fraction alloys utilizing the modulated photocurrent method to monitor the individual changes in the Si and Ge deep defects. By relating the metastable creation and annealing behavior of these two types of defects, new insights into the fundamental properties of metastable defects have been obtained for amorphous silicon materials in general. I will conclude with a brief discussion of the microscopic mechanisms that may be responsible.

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