Carrier‐Selective Contact Based Silicon Solar Cells Processed at Room Temperature using Industrially Feasible Cz Wafers

Abstract

For the broad use of solar photovoltaic devices, the device fabricated at commercially viable silicon wafers at room temperature is more preferable to harvest abundant solar energy. Silicon heterojunction solar cells at room temperature, based on carrier‐selective layers without using any specified surface passivation layer on the silicon wafer is fabricated. Industrially feasible Cz n‐type non‐textured silicon wafers having the bulk lifetime of 300 µs are used for cell fabrication. The molybdenum oxide (MoOx) and lithium fluoride (LiFx) are used as hole‐ and electron‐selective layers, respectively. The highest conversion efficiency of >15% from the simple architecture of Ag/TCO/MoOx/n‐Si/LiFx/Al is achieved. The internal quantum efficiency of ≈96% is observed in the shorter wavelength region, whereas to understand relatively less response between 800 and 1100 nm wavelength region; effective minority carrier diffusion lengths are estimated. The authors also confirm the inversion layer formation in the silicon after MoOx contact from temperature dependent capacitance‐voltage measurements, and quantify the crucial built‐in‐potential of ≈0.69 V from the cell structure due to the high work function of MoOx layer.