钠诱导的掺钨氧化铟薄膜及异质结太阳能电池在湿热环境中的退化

Abstract The reliability of silicon heterojunction (HJT) solar cells is the key to extending the lifetime of their photovoltaic systems. Sodium is considered to be one of the main factors in the attenuation of PV modules encapsulated with soda-lime glass. This work investigated the NaHCO 3 -induced degradation of unencapsulated HJT solar cells at damp-heat conditions (DH, 85 °C and 85 % relative humidity). Chemisorption of Na + and H 2 O at the grain boundaries of IWO films can promote the transformation of indium oxide into indium hydroxide, causing the degradation of carrier mobility and the increase in grain boundary barrier. Furthermore, the diffusion of Na + through the IWO film into the passivation layer of the HJT solar cell deteriorates the passivation effect of nc-Si:H, resulting in a decrease in the efficiency of the HJT solar cell. It is found that IWO films with the large-size grains can effectively withstand Na + aging. When the grain size of IWO increases from 36.0 nm to 56.1 nm, the degradation of HJT solar cell efficiency due to Na + will be reduced from 71.4 % rel to 36.6 % rel . This study provides important insights into the degradation mechanisms of HJT solar cell, which is critical for optimizing performance and enhancing the long-term reliability of HJT modules.