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Showing 1 to 18 of 18 for “"Amorphous semiconductors."”.
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Optical Transitions in Amorphous Semiconductors
… analysis of the optical response of an amorphous semiconductor is presented. The entire analysis is cast within the framework of an empirical model for the valence band and conduction band density of states functions, that captures the basic features expected of these functions. A novel …
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Vibrations in elemental amorphous semiconductors
… to structural models of the elemental amorphous semiconductors a-Ge, a-As and a-Se are presented. Simple dynamical models, involving restoring forces for bond length and angle variations only, provide information on the structure-dependence of the vibrational spectra and hence on the …
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Time and frequency resolved photoconductivity studies on amorphous semiconductors
… trapping and recombination parameters of amorphous semiconductors. The solution of the linearised multiple trapping rate equations is straightforward in the frequency domain, and it is simple to invert the modulated photoconductivity (MPC) response to obtain an accurate DOS. It is proposed …
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Carrier mobility of downscaled amorphous semiconductors exemplified by hydrogenated amorphous silicon
… Internet of Things (IoT) facilities. Amorphous semiconductors are among the most favoured channel semiconductors in TFTs because of their irreplaceable merits such as large-area uniformity, low cost and low thermal budget which are essential to the above use cases. Nevertheless, the …
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Investigation of the suitability of amorphous semiconductors as sensors for optical process tomography
In this work, the suitability of amorphous semiconductors as hard field optical sensors for application in optical process tomography (OPT) has been established. Two amorphous semiconductors were selected for the study, these being amorphous arsenic triselenide (a-As 2 Se3) and hydrogenated …
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Transport Characteristics of Amorphous Semiconductors in the Dilute Carrier Regime: A Variable Range Hopping Treatment
… which are used to find the conductivity of amorphous solids as a function of temperature, specifically the work done by N. F. Mott and Apsley et al. and we point out the problems with deriving such a relationship. We then develop a self consistent numerical system for calculating the charge …
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A STUDY OF SWITCHING PHENOMENA IN DISCONTINUOUS AU AND TI FILMS
… Presently, researchers are concentrating on the amorphous semiconductors. However, switching properties have been reported in discontinuous thin metal films, and this thesis reports on results for discontinuous gold and discontinuous titanium. Due to apparent similarities in the operation of …
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Polaron transport in silver bromide
… applied to study the mechanism of conduction in amorphous semiconductors. The steep decline in Hall mobility observed at intermediate temperatures indicate the predominance of carrier scattering by longitudinal optical (LO) phonons. The Debye temperature of LO phonons, deduced from present data, …
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ΦΑΙΝΟΜΕΝΑ ΜΕΤΑΦΟΡΑΣ ΑΜΟΡΦΩΝ ΗΜΙΑΓΩΓΩΝ
… ADOPTICAL ABSORPTION WERE APPLIED TO SPUTTERED AMORPHOUS GE SE BIX AND AMORPHOUS HYDROGENATED SILICON A-SI:H FILMS FROM GLOW DISCHARGE. IT WAS FOUND THAT ADDITION OF 15,6 AT % BI LEADS TO AN INCREASE OF TEN ORDERSOF MAGNITUDE IN ELECTRICAL CONDUCTIVITY AS WELL AS A DECREASE IN THE OPTICAL GAPS. …
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Novel Inorganic Photoresists for Three-Dimensional Microfabrication
… of resists consists of chalcogenide glass based amorphous semiconductors from the As-S-Se ternary system. The structures formed using this system have a high index of refraction and strongly non-linear optical properties, making them attractive candidates for engineered photonic crystal based …
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Physics and simulation of transport processes in hybrid organic semiconductor devices
Organic semiconductors and nanomaterials promise to potentially form the basis for future efficient and cost-effective large area optoelectronic devices, such as lightemitting diodes and solar cells. Although these materials' amorphous nature allow utilization of cheap, high-throughput …
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Pulsed laser deposition of chalcogenide glass materials for potential waveguide laser applications
… state, rare earth laser device. <br/><br/>These amorphous semiconductors have a transmission range from the visible through to the mid infrared part of the spectrum. Chalcogenides can be photomodified. i.e. they have an ability to change refractive index when illuminated with photons whose …
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Computer modelling and experimental characterisation of amorphous semiconductor thin films and devices
Computer source codes for modelling amorphous semiconductors have been developed during the course of the study. The major program <i>SPIN.F</i> deals with steady state electronic processes for amorphous semiconductor materials and devices under different optical excitation and applied voltage …
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Probing localized states distributions in semiconductors by Laplace transform transient photocurrent spectroscopy
… question of how the disorder of non-crystalline semiconductors influences their electronic properties. The concept of the mobility edge and mobility gap is introduced and a definition of the density of electronic states (DOS) is given. The DOS will be referred to frequently in this work. Also …
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Transit Dosimetry for Patient Treatment Verification with an Electronic Portal Imaging Device
… identifying the correct patient for treatment. Amorphous silicon (aSi) Electronic Portal Imaging Devices (EPIDs) can be utilized for IMRT verification. The goal of this thesis is to implement EPID transit dosimetry, measurement of the dose at a plane behind the patient during their treatment, …
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A study of hydrogenated nanocrystalline silicon thin films deposited by hot-wire chemical vapour deposition (HWCVD)
… some aspects (mainly optical) to its counterpart amorphous silicon actually used as the intrinsic layer in the photovoltaic industry. Substantial differences between the two materials have been found however in their respective structural and electronic properties. We show that hydrogenated …
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Adherence/Diffusion Barrier Layers for Copper Metallization: Amorphous Carbon:Silicon Polymerized Films
… Cu wetting. This study proposes modified amorphous silicon carbon hydrogen (a-Si:C:H) films as possible diffusion barriers and replacements for SiO2 between metal levels, interlevel dielectric (ILD), or between metal lines (IMD), based upon the diffusion inhibition of previous a-Si:C:H …