Preparation of UV cutoff anti-reflective coatings by sol-gel method in view of silicon heterojunction solar cells

Silicon heterojunction (SHJ) solar cells employ a hydrogenated amorphous silicon (a-Si:H) layer to achieve highly efficient passivation of the crystalline silicon (c-Si) surface, thereby enabling high open-circuit voltage (V OC ). However, during long-term operation, the intrinsic amorphous silicon (i-a-Si) passivation layer is susceptible to degradation under ultraviolet (UV) irradiation, resulting in performance decline. To mitigate this issue, the present study develops a ZnO-based anti-reflective (AR) UV cutoff multilayer film. A zinc oxide (ZnO) precursor is prepared via a simple sol-gel method, and subsequently subjected to high-temperature curing to form a uniform coating on the glass surface. An additional AR layer is then deposited using the same process to further enhance transmittance and weather resistance. Experimental results demonstrate that the fabricated ZnO-AR film exhibits significantly reduced transmittance in the 250 nm - 380 nm UV band while maintaining an average transmittance of 94.52% in the 380 nm - 1100 nm visible-to-near-infrared range. The film also shows excellent environmental stability, with performance retained after high-temperature, high-humidity, and UV aging tests. SHJ cells coated with this film achieve a short-circuit current density of 37.27 mA cm −2 , representing a 5.16% improvement compared to cells with uncoated glass. Given its straightforward fabrication process and robust weather resistance, this approach offers effective technical support for the practical outdoor deployment of SHJ solar cells.