Defects in Amorphous Semiconductors: Amorphous Silicon

2006 ◽  
pp. 245-268 ◽  
Author(s):  
D.A. Drabold ◽  
T.A. Abtew
Keyword(s):  
Amorphous Silicon ◽  
Amorphous Semiconductors

The Structure of Ion-Implanted Amorphous Silicon

1998 ◽  
Vol 540 ◽  
Author(s):  
J. M. Gibson ◽  
J-Y. Cheng ◽  
P. Voyles ◽  
M.M.J. TREACY ◽  
D.C. Jacobson
Keyword(s):  
Amorphous Silicon ◽  
Network Model ◽  
Random Network ◽  
Amorphous Semiconductors ◽  
Range Order ◽  
Medium Range Order ◽  
Medium Range ◽  
Large Heat ◽  
Continuous Random Network ◽  
Ion Implanted

AbstractUsing fluctuation microscopy, we show that ion-implanted amorphous silicon has more medium-range order than is expected from the continuous random network model. From our previous work on evaporated and sputtered amorphous silicon, we conclude that the structure is paracrystalline, i.e. it possesses crystalline-like order which decays with distance from any point. The observation might pose an explanation for the large heat of relaxation that is evolved by ion-implanted amorphous semiconductors.

scholarly journals Photoluminescent Properties of Hydrogenated Amorphous Silicon Oxide Powders

2002 ◽  
Vol 17 (5) ◽  
pp. 977-980 ◽  
Author(s):  
Wei-Fang Su ◽  
Hong-Ru Guo
Keyword(s):  
Amorphous Silicon ◽  
Silicon Oxide ◽  
Hydrogenated Amorphous Silicon ◽  
Thermal Quenching ◽  
Amorphous Semiconductors ◽  
Electronic Density ◽  
Quenching Effect ◽  
Oxide Powders ◽  
Amorphous Silicon Oxide ◽  
Hydrogenated Amorphous

The photoluminescence properties of hydrogenated amorphous silicon oxide powder SiO0.92H0.53 were investigated. The powder was prepared by reacting lithium with trichlorosilane in tetrahydrofuran. The luminescence peak energy was located between 1.0 and 1.61 eV. The samples were treated under different conditions such as annealing, hydrolysis, and hydrolysis plus HF etching. The changes of the photoluminescent intensity and location on the treated powders can be explained by the electronic density of state model of amorphous semiconductors. The temperature dependence of luminescence properties of the powders can be described by the relationship of thermal quenching effect: ln[Io/I(T) – 1] = ED/Eo = T/To at temperatures between 100 and 300 K.

Hydrogen Microstructure in Amorphous Semiconductors.

1987 ◽  
Vol 95 ◽  
Author(s):  
Karen K. Gleason ◽  
Mark A. Petrich ◽  
Jeffrey A. Reimer
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Amorphous Silicon ◽  
Deposition Temperature ◽  
Annealing Temperature ◽  
Amorphous Semiconductors ◽  
Multiple Quantum ◽  
Deposition Parameters ◽  
Dopant Atoms ◽  
Lower Temperature ◽  
Small Clusters

AbstractThe effects of deposition parameters on the H microstructure of plasma deposited amorphous silicon (a-Si:H) and amorphous silicon carbide (a-SiC:H) are measured via multiple quantum nuclear magnetic resonance (MQ NMR). These studies indicate clusters of 5 to 7H atoms exist in a-Si:H films prepared at temperatures ranging from 113 to 324°C. In the range from 270 to 324°C, only these small clusters exist, but lower temperature films also contain larger clusters. Annealing studies indicate H rearranges in a-Si:H prior to evolution. Deposition temperature and annealing temperature have similar effects on H concentration in a-Si:H, but deposition temperature control the density and microstructure of the film. The addition of dopant atoms also affects the H microstructure, with phosphorous causing larger H clusters to form, and boron reducing clustering in a-Si:H films. This perturbation of the film's microstructure suggests that the effects of dopant addition are more complex in amorphous than in crystalline semiconductors. The concentration of carbon atoms also effects H microstructure of a-SiC:H in a complex way. We surmise that H microstructure, rather than H content, determines amorphous semiconductors properties.

Temperature Dependent Carrier Transport in Hydrogenated Amorphous Semiconductors for Thin Film Memristive Applications

2022 ◽  
Vol 1048 ◽  
pp. 182-188
Author(s):  
Mayank Chakraverty ◽  
V.N. Ramakrishnan
Keyword(s):  
Amorphous Silicon ◽  
Amorphous Materials ◽  
Carrier Transport ◽  
Hole Concentration ◽  
Hydrogenated Amorphous Silicon ◽  
Amorphous Semiconductors ◽  
Effect Of Temperature ◽  
Temperature Dependent ◽  
Different Temperatures ◽  
Hydrogenated Amorphous

This paper demonstrates the transport of electron and hole carriers in two distinct hydrogenated amorphous semiconductor materials at different temperatures. Compared to crystalline materials, the amorphous semiconductors differ structurally, optically and electrically, hence the nature of carrier transport through such amorphous materials differ. Materials like hydrogenated amorphous silicon and amorphous IGZO have been used for the study of temperature dependent carrier transport in this paper. Simulation results have been presented to show the variation of free electron and hole concentration, trapped electron and hole concentration with energy at 300K for both the materials. The change in mobility with a change in the Fermi level has been plotted for different temperatures. The effect of temperature on Brownian motion mobility of electrons and holes in hydrogenated amorphous silicon and amorphous IGZO has been demonstrated towards the end of this paper.

Characterization of the Activation-Relaxation Technique: Recent Results on Models of Amorphous Silicon

2001 ◽  
Vol 677 ◽  
Author(s):  
Rachid Malek ◽  
Normand Mousseau ◽  
G. T. Barkema
Keyword(s):  
Amorphous Silicon ◽  
Detailed Analysis ◽  
Saddle Points ◽  
Amorphous Semiconductors ◽  
Relaxation Technique ◽  
Energy Landscapes ◽  
Lennard Jones ◽  
Wide Range

ABSTRACTThe activation-relaxation technique (ART) is a method for finding saddle points in high-dimen- sional energy landscapes. ART has already been applied to a wide range of materials including amorphous semiconductors, Lennard-Jones glasses, and proteins. In spite of its successes, a number of fundamental questions remain to be answered regarding the biases associated with its sampling of the saddle points. We present here results of a detailed analysis of the biases in the simulation of amorphous silicon. We focus in particular on the biases of the method in sampling saddle points, the completeness of the sampling and the sensitivity of these quantities to variations of the different parameters.

Magnetic Resonance Probes Of Band Tail States And Defects In Tetrahedrally Coordinated Amorphous Semiconductors

2002 ◽  
Vol 715 ◽  
Author(s):  
P. C. Taylor
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Amorphous Semiconductors ◽  
Dangling Bonds ◽  
Band Tail ◽  
Wide Range ◽  
Recombination Processes ◽  
Staebler Wronski Effect ◽  
Hydrogenated Amorphous ◽  
Kinetics Of

AbstractRecent electron spin resonance (ESR) results relating to (1) recombination processes for optically excited electrons and holes in tetrahedrally coordinated amorphous semiconductors and (2) kinetics of metastable defects (dangling bonds associated with the Staebler-Wronski effect) in hydrogenated amorphous silicon (a-Si:H). With regard to recombination processes, ESR measurements have been performed over a wide range of excitation intensities (nW/cm2 to W/cm2) on hydrogenated amorphous silicon (a-Si:H) and hydrogenated amorphous germanium (a-Ge:H). The kinetics can be studied down to carrier densities as low as 1014 cm-3. The longtime decay curves show that at large carrier separation (1) the random distribution of optically excited electrons and holes is subject to the condition of charge neutrality, and (2) the decays are universal and independent of the densities of localized, band-tail states. With regard to the metastable defects in a-Si:H, the kinetics of the production and thermal annealing of silicon dangling bonds have been measured at temperatures between 25 and 480 K using ESR. Below about 150 K the measurement of the dangling bonds is masked by long-lived, band tail carriers that accumulate with time. The production rate for silicon dangling bonds decreases with decreasing temperature and is nearly temperature independent below approximately 100 K. Defects created by 10 hours of irradiation below 100 K anneal almost completely at 300 K. In a- Ge:H, the first measurements of optically induced, metastable germanium dangling bonds have been made.

scholarly journals Magnetic Susceptibility of Tetrahedrally Bonded Amorphous Semiconductors

1995 ◽  
Vol 17 (4) ◽  
pp. 253-255 ◽  
Author(s):  
M. A. Grado Caffaro ◽  
M. Grado Caffaro
Keyword(s):  
Magnetic Susceptibility ◽  
Electron Spin Resonance ◽  
Amorphous Silicon ◽  
Electron Spin ◽  
Amorphous Semiconductors ◽  
Theoretical Formulation ◽  
Paramagnetic Contribution ◽  
Spin Resonance ◽  
Tetrahedrally Bonded

A special theoretical formulation on the magnetic susceptibility of tetrahedral amorphous semiconductors is proposed. This formulation is based upon a Wannier representation involving two terms: a diamagnetic term and a paramagnetic contribution. In addition, electron-spin resonance referred to amorphous silicon is considered.

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