Enhancing multi-crystalline silicon wafer performance through surface modification and AZO treatment

Abstract

In the current work, we studied the influence of surface modification on reflectivity and minority carrier lifetime of mc-Si wafer taken from ingot grown by DS process. Two etchants combination namely, KOH/IPA/DI water, and NaOCl/KOH/IPA/DI water are used for different time durations. Reflectance and minority carrier lifetime vary significantly for both etchants used in this work. Optimised micro pyramidal structure formation will aid in enhancing the total internal reflection thereby increasing light absorption. Increase in minority carrier lifetime will be helpful in increasing the efficiency of solar cell. In order to establish the effect of etching on reflectivity of wafers, Al-doped ZnO was sputtered on etched surface and reflectivity was found to decrease further as observed from the reflectivity spectrum. I-V measurements were carried out on Ag/Ti/AZO/mc-Si/Ag and effect of etching on contact behaviour was observed. AZO-coated Si surface with optimised surface micro pyramids served as a good antireflection layer..