期刊名称：Journal of Materials and Environmental Science
印刷版ISSN：2028-2508
出版年度：2017
卷号：8
期号：3
页码：809-815
出版社：University of Mohammed Premier Oujda
摘要：Tunneling effect is an important process in degenerate semiconductors, especially whenthe electrical field in space charge regions is very strong (upper than 109 V.cm-1) anddoping is higher (upper than 1019 cm-3). This paper provides a detailed description oftunneling mechanisms in a multi-junction structure. It takes into account the band-to-bandtunneling effect and the traps-assisted tunneling process through discrete states located inthe bandgap. The numerical algorithm is based on a one-dimensional steady state driftdiffusion model and uses the Fermi-Dirac statistics to describe carrier’s transport insemiconductors. The use of this distribution leads to an integral calculation which cannotbe evaluated analytically and needs special numerical methods. Our model employs also ageneralized Scharfetter-Gummel discretization scheme, which is consistent with bothequilibrium and non-equilibrium cases. Numerical tests have been carried out on a multijunctionstructure with different levels of doping including layers with degenerate andnon-degenerate semiconductors. Different parameters and electrical characterizationshave been simulated to examine the contribution of these effects in the performance of thestructure. It is shown that extended Scharfetter-Gummel scheme is stable convergent. Onthe other hand, adding tunneling effect shows the predicted peak and valley in the I-Vcurve.
