Experimental and Simulation Analysis of Thermal Vertical Directional Solidification Grown Ni Doped Gasb

Due to high hole mobility, p-GaSb is an attractive III-V semiconducting material for high performance p-channel metal-oxide semiconductor field effect transistor (p-MOSFET). For that growth of undoped and Ni doped GaSb bulk crystal by thermal vertical directional solidification technique has been reported in this paper. X-ray diffraction (XRD) analysis confirms that the both grown compounds are polycrystalline in nature which have been supported by scanning electron microscope (SEM) image. The carrier charge density and mobility were measured by Hall Effect measurement in the temperature range 78K and 300K. From the sign of Hall co-efficient the both grown materials were confirmed p-type. The Current-Voltage (I-V) characteristic was studied for both the sample i.e. experimentally grown and also simulated using TCAD at 78K and 300K. The temperature dependence of the hole mobility were also investigated by TCAD tool using the models Auger recombination, Shockley-Read-Hall (SRH) and Band-gap narrowing (BGN). Comparison of experimental and simulated temperature dependencies of mobility shows good agreement, while their differences at some points suggests the contribution of compensating impurities.

Charge Carrier Mobility Analysis of Chlorophyll Thin Film Spirulina sp Produced by Spin Coating

<span>Analysis of carrier charge mobility of <span><em>Spirulina sp </em><span>thin films produced by spin coating have<br /><span>been conducted. Measurement of carrier charge mobility has been done by <span><em>I</em><span>-<span><em>V </em><span>method.<br /><span>Mobility of carrier charge decreased with an increased of the layer number. It indicates that a<br /><span>threshold value of carrier charge of population number over flow on conduction band.</span></span></span><br /></span></span></span></span></span></span></span>

Magneto-Conductance Effect of Natural Porphyrin Thin Films Fabricated by Spin Coated Method

We present magneto conductivity measurements in natural porphyrin thin films in magnetic fields of 100 Oe at room-temperature. The films used in this experiment were isolated from natural spirulina sp by chromatography procedure with n-hexane. Each layer fabricated by spin coater methods with rotation speed of 2500 rpm for 60 second is followed post heating at temperature of 60°C for 300 second. The procedure is repeated N times. Magneto-conductance effect is presented at room temperature with induce magnetic field in plane of films. The results show that ratio magneto-conductance decreases with the increase of voltage provided. The magneto-conductance ratio increase with the increase of N repetition number. Finally, both the results indicate that magneto-conductance effect could be realized due to annihilation of carrier charge.

Development of High-Voltage 4H-SiC GTOs for Grid-Tied Solar Inverters

A growing demand for smart and flexible photovoltaic power conversion and pulsed-power systems is leading to rapid development and commercialization of medium voltage 6.5 - 24 kV, wide-bang gap rectifiers and switches. Conventional silicon bipolar switches are limited to roughly 8 kV breakdown voltages and scaling up the voltage rating requires very thick wafers presenting significant manufacturing challenges. Very thick drift layers of silicon devices also translate into a very high minority carrier charge injected during forward conduction for an efficient conductivity modulation, hence leading to an extremely slow switching speed and poor efficiency. In this paper USCi presents the development of 6.5 kV 4H-SiC gate-turn-off thyristors (GTOs) with multiple floating guard-ring edge termination, and describes their application in an AC-link grid-tied solar inverter system.

MODELING HETEROSTRUCTURES WITH SCHRÖDINGER–POISSON–NAVIER ITERATIVE SCHEMES, EFFECT OF CARRIER CHARGE, AND INFLUENCE OF ELECTROMECHANICAL COUPLING

This paper presents a detailed investigation of the effects of piezoelectricity, spontaneous polarization and charge density on the electronic states and the quasi-Fermi level energy in wurtzite-type semiconductor heterojunctions. This has required a full solution to the coupled Schrödinger–Poisson–Navier model, as a generalization of earlier work on the Schrödinger–Poisson problem. Finite-element-based simulations have been performed on a AlN/GaN quantum well by using both one-step calculation as well as the self-consistent iterative scheme. Results have been provided for field distributions corresponding to cases with zero-displacement boundary conditions and also stress-free boundary conditions. It has been further demonstrated by using four case study examples that a complete self-consistent coupling of electromechanical fields is essential to accurately capture the electromechanical fields and electronic wavefunctions. We have demonstrated that electronic energies can change up to approximately 0.5 eV when comparing partial and complete coupling of electromechanical fields. Similarly, wavefunctions are significantly altered when following a self-consistent procedure as opposed to the partial-coupling case usually considered in literature. Hence, a complete self-consistent procedure is necessary when addressing problems requiring more accurate results on optoelectronic properties of low-dimensional nanostructures compared to those obtainable with conventional methodologies.