Characterization and optimization of ITO thin films for application in heterojunction silicon solar cells

This investigation elucidates the properties of indium–tin oxide (ITO) thin films used as antireflection front electrodes in μc-Si/c-Si heterojunction (HJ) solar cells. The deposition conditions of ITO film by electron-gun evaporation were optimized for HJ solar cell applications. Microstructure, surface morphology, electrical and optical properties of these films were then characterized and analyzed. Next, the effects of substrate temperature on ITO film growth were discussed. The ITO thickness was optimized considering that the refractive index of μc-Si emitter layer optimizes its optical characteristics and HJ solar cell spectral response. The best HJ solar cell conversion efficiency was 16.4% with an open circuit voltage (Voc) of 0.645 V, fill factor (FF) of 0.73, and short circuit current density (Jsc) of 34.8 mA/cm2.