Modeling and optimization of core/shell p-i-n Si/Si0.2Ge0.8 nanowire for photovoltaic

In this work we propose a modeling and simulation of core/shell p-i-n Si/Si0.2Ge0.8 nanowire for photovoltaic. In the first step of this work, we have compared the core/shell p-i-n homojunction Si and heterojunction Si/Si0.2Ge0.8 Nanowire (NW) solar cell having a length of 3 μm and a radius of 0.19 μm, by studying their current-voltage and external quantum efficiency (EQE). Our results have shown that blending Silicon with 80% of Germanium enhances relatively the short circuit current and efficiency by 3.04% and 8.48% respectively. In other hand, the absorption edge of Silicon NW has extended from 1100 nm to 1200 nm, with a gain of EQE of 15% obtained in this range. In the second part, we have tried to optimize the Si/Si0.2Ge0.8 structure, by varying their radius and length. The corresponding results have indicated that a radius of 0.28 μm and a length of 10 μm are the optimal geometric parameters for any optimization of such structure.