Improved optical and electrical properties for heterojunction solar cell using Al2O3/ITO double-layer anti-reflective coating

Silicon heterojunction solar cells have been gaining remarkable attention in the photovoltaic industry in recent years owing to their low temperature coefficient and high efficiency. This study aimed to maximize the short circuit current density (J_sc), which is directly correlated with the absorbance of the solar cells. An advanced ray tracking model and hall effect measurement was used to improve the optical properties of Al₂O₃/ITO as a double-layered anti-reflection coating (DLARC) on the solar cell. RF/DC power sputtering system was used to deposit ITO layer, while atomic layer deposition was used to deposit Al₂O₃ on ITO to create a DLARC. An average decrease in reflection from 9.33% to 4.74% and enhancement in EQE from 76.89% to 84.34% were observed for the DLARC in the wavelength spectrum at 300-1100 nm. It also exhibited a higher J_sc value of 41.13 mA/cm² and maximum conversion efficiency of 21.6%. The findings of both simulation and experiments showed that the Al₂O₃/ITO DLARC has better anti-reflection properties than a single-layer ITO coating.