Effect of wide-bandgap of n-type amorphous silicon oxide (a-SiOx:H) layer on the performance of a-Si:H solar cell

Abstract

In p-i-n a-Si:H solar cells, the different optical and electrical losses can be limited by using the wide bandgap a-Si:H alloys as doped layers. This study aims to explore the optoelectronic proprieties of hydrogenated amorphous silicon oxide (a-SiOx:H) for minimizing the optical and electrical losses in solar cell-based a-Si:H, in particular at n/i region. In this context, wxAMPS simulator is used to optimize the properties of the different layers of a-Si:H solar cell, especially n-type layer. The developed a-SiO:H has high photosensitivity and high band gap of 1.95eV, which contributed to attain remarkable fill factor (FF) and high open circuit voltage (V_OC). As a result, an efficiency of 12.28 [%] was achieved. Even though, the short circuit courant Jsc is decreased, the high photosensitivity and wide band gap of a-SiOx:H n-layer offered a high V_OC of 0.97V. In addition, the efficiency could be improved up to 12.3% by inserting a very thin non-doped a-SiOx:H at n/i interfaces, which offers better short circuit currents in the solar cell.