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Surface Recombination (surface + recombination)
Selected AbstractsStochastic and Relaxation Processes in Argon by Measurements of Dynamic Breakdown VoltagesCONTRIBUTIONS TO PLASMA PHYSICS, Issue 7 2005V. Lj. Abstract Statistically based measurements of breakdown voltages Ub and breakdown delay times td and their variations in transient regimes of establishment and relaxation of discharges are a convenient method to study stochastic processes of electrical breakdown of gases, as well as relaxation kinetics in afterglow. In this paper the measurements and statistical analysis of the dynamic breakdown voltages Ub for linearly rising (ramp) pulses in argon at 1.33 mbar and the rates of voltage rise k up to 800 V s,1 are presented. It was found that electrical breakdowns by linearly rising (ramp) pulses is an inhomogeneous Poisson process caused by primary and secondary ionization coefficients , , , and electron yield Y variations on the voltage (time). The experimental breakdown voltage distributions were fitted by theoretical distributions by applying approximate analytical and numerical models. The afterglow kinetics in argon was studied based on the dependence of the initial electron yield on the relaxation time Y0 (, ) derived from fitting of distributions. The space charge decay was explained by the surface recombination of nitrogen atoms present as impurities. The afterglow kinetics and the surface recombination coefficients on the gas tube and cathode were determined from a gas-phase model. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Analysis of GaInAsP laser diodes degraded by light absorption at an active layer of the facetELECTRONICS & COMMUNICATIONS IN JAPAN, Issue 2 2010Hiroyuki Ichikawa Abstract Electrostatic discharge-induced degradation is one of the serious reliability problems of GaInAsP/InP laser diodes. The authors have conducted an analysis of electrostatic discharge-induced degradation, and have elucidated the principal degradation mechanism. The main cause of degradation is heating by light absorption at the active layer of the facet. This phenomenon is similar to the catastrophic optical damage that occurs in GaAs-based high-power laser diodes. The problem has become more serious with the recent tendency to high power demand. Therefore, technology to suppress against degradation is extremely important. Focusing on facet coating, which is one of the key processes to suppress facet degradation, we demonstrated that facet degradation can be successfully suppressed by inserting an ultrathin aluminum layer between the semiconductor and the dielectric coaling films. This effect is caused by a reduction of surface recombination. This degradation suppression technology has the potential to be applied not only to GaInAsP/InP laser diodes, but to any InP-based laser diodes. © 2010 Wiley Periodicals, Inc. Electron Comm Jpn, 93(2): 32,38, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecj.10196 [source] High efficiency all-GaAs solar cellPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 2 2010Abderrahmane Belghachi Abstract The reduction of surface recombination in GaAs solar cells is known to be a major concern for photovoltaic cells designers. A common technique used to reduce this effect is to cover the GaAs surface with a wide band gap window layer, therefore the creation of a heterojunction. To avoid a heterojunction with its inconveniences; interface surface states, poor photon absorption in addition to the technological exigencies, one can use an all-GaAs solar cell. In this type of structure, a thin highly doped layer is created at the surface known as a front surface field (FSF). The main role of an FSF layer is to reduce the effect of front surface recombination and the enhancement of light-generated free carriers' collection. This is achieved by the drastic reduction of the effective recombination at the emitter upper boundary. In this work, a simple analytical model is used to simulate the influence of the FSF layer on GaAs solar cell parameters; photocurrent, open circuit voltage and energy conversion efficiency. The effects of the FSF layer doping density and its thickness on the cell performance are discussed by using computed results. Copyright © 2010 John Wiley & Sons, Ltd. [source] Limiting efficiency of crystalline silicon solar cells due to Coulomb-enhanced Auger recombinationPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 2 2003Mark J. Kerr Excitonic effects are known to enhance the rate of intrinsic recombination processes in crystalline silicon. New calculations for the limiting efficiency of silicon solar cells are presented here, based on a recent parameterization for the Coulomb-enhanced Auger recombination rate, which accounts for its dopant type and dopant density dependence at an arbitrary injection level. Radiative recombination has been included along with photon recycling effects modeled by three-dimensional ray tracing. A maximum cell efficiency of 29.05% has been calculated for a 90-,m-thick cell made from high resistivity silicon at 25°C. For 1,,,cm p -type silicon, the maximum efficiency reduces from 28.6% for a 55-,m-thick cell in the absence of surface recombination, down to 27.0% for a thickness in the range 300,500,,m when surface recombination limits the open-circuit voltage to 720,mV. Copyright © 2002 John Wiley & Sons, Ltd. [source] | ||||||||||