Preparation and stability study of broadband anti-reflection coatings and application research for CdTe solar cell

Abstract

Reflection loss is essential factor to limit the efficiency of all of photovoltaic devices. Glass substrate that with no trapping mechanism to reduce the reflection of light as most CdTe commercial thin film solar cells are manufactured. The absorption band gap of CdTe devices is 387–850 nm, to minimize the losses, a broadband anti-reflection coating that its transmittance must as high as possible at 390–850 nm is designed with TFCALC modeling software and deposited with sol-gel method and dip-coatings technique on both sides of the glass substrate. See from the transmittance spectrum of broadband anti-reflection coatings (BARCs) is more than 98% at the band of 390–870 nm which is the same as the band gap of CdTe photovoltaic cells and its maximum transmittance is 99.70%. In addition to matched band and high transmittance, the durability of BARCs is crucial for applying on CdTe devices. It presents that BARCs that uses trimethyl chlorosilane (TMCS) to optimize the hydrophilic of the surface of BARCs is relatively stable from the examination of Contact angle and Environmental include damp heat, ultraviolet radiation and light-tact. The BARCs can well apply on CdTe modules that the optical property of BARCs is not affected by the preparation process of CdTe solar cell with simulation.