An Enhanced Conversion Efficiency of Metal Insulator Semiconductor Solar Cells by Using Different High-K Dielectrics

In this paper, the role of different high-k materials in enhancing the efficiency of a metal insulator semiconductor (MIS) solar cell is investigated in detail. In order to overcome the traditional SiO2 disadvantages, alternative dielectrics, namely TiO2, Si3N4, and Ta2O5, with a thickness of 10 Å are used. Furthermore, the effect of the interface states density, doping density, and oxide fixed charge on the electrical outputs of the proposed MIS solar cell is assessed. The simulation results indicate that Ta2O5 could be a good candidate to replace SiO2. The optimized design of a 250-μm-thick cell structure, with a p-type substrate with a doping density of 7 × 1015 cm−3 and a Ta2O5layeras dielectric, performs a short circuit currentdensity JSC = 44.35 mA/cm2, an open circuit voltage VOC = 0.59 V,a fill factor FF = 81.19%, and a conversion efficiency η = 21.54%. Besides, to get a broad perspective on the device optimization possibility, an investigation on a suitable metal work function is also carried out in this study. In particular, a metal electrode with a low work function could efficiently improve the device VOC value.