Simplification of high graphene/n-Si Schottky junction solar efficiency

Abstract

Because of the outstanding properties of graphene such as optical transmission and mobility of charges [1], it incorporates to Schottky solar cells. These properties of graphene also reduces the optical and electrical losses which are in solar cells made of p-n structures. To increase the performance of electronic devices, researchers developed 3 designs using graphene with silicon solar cell technology. Schottky junction solar cells made of graphene and n-silicon have attained efficiency values comparable to p-n junction silicon solar cells. Nevertheless, issues remain such as how to simplify the creating process to improve the fill factor and stability of devices. This doctoral study will focus on various phases of the progression of graphene/silicon solar cells toward greater efficiency and stability. The study will discuss the simplicity of top-window-structured graphene/n-Si Schottky junction photovoltaic devices. It will also deal with developing the fill factor and stability of devices. Until now, top window devices have required complex preparation processes for SiO2 including etching a part of it to create the top window design. To accomplish the process, a simple method of sputtering to form coated SiO2 layers has been developed and will be described in this study. The thickness of SiO2 is thoroughly investigated to constitute an effective top window design. This research is also conducted to enhance the fill factor of samples after introducing multi-graphene layers which form the Schottky junction. This was achieved after decreasing the amount of PMMA residue by developed techniques such as annealing, DUV and chemical treatments. Evaporation of chemical dopants which was another problem that causes low stability of doped devices within a week. It was found in this work that a layer of PMMA coated onto prepared devices significantly improves the stability of doped samples