Enhancing the quantum efficiency of a silicon solar cell using one dimensional thin film interferometry

Abstract

Crystalline silicon solar cells are prominent renewable energy sources that convert solar energy into electrical energy without emitting greenhouse gases. They are used to energize satellites as well as provide electricity for buildings, local areas/settlements, and remote locations. However, the efficiency of these solar cells is limited by two factors: light reflection at the Si-Air interface, which reduces energy absorption, and the recombination rate of electron-hole pairs that reduces the mobile charge carriers available for electricity conduction. Solar cell expenses are comparable to conventional energy resources, motivating research to increase solar cell efficiency for commercial viability. The goal of our study was to increase crystalline solar cell efficiency theoretically by simulation. We mathematically simulated an omni-directional reflector with alternate Si/SiO2 layers using multi-layered thin film interferometry in MATLAB, which was designed to reflect wavelengths in the range of 628 nm to 808 nm. We found that the ODR’s energy reflected more energy at a central wavelength of 800 nm and 8 total layers. We also simulated an anti-reflection coating layer for the top of the solar cell using alternate ZnO-SiO2 multilayers for enhanced transmission in the range of 481 nm to 2000 nm to increase solar cell efficiency for various optoelectronic devices and thermo-photovoltaic applications. We found that this reduced the reflectivity of the Si-Air interface by 49%.