光电子学
硅
光伏系统
异质结
太阳能电池
p-n结
电压
能量转换效率
二极管
开路电压
作者
Seira Yamaguchi,Kyotaro Nakamura,Atsushi Masuda,Keisuke Ohdaira
标识
DOI:10.7567/jjap.57.122301
摘要
In this study, we investigated progression of potential-induced degradation (PID) in photovoltaic modules fabricated from n-type-based crystalline-silicon cells with front p+ emitters. In PID tests in which a bias of −1000 V was applied to the modules, they started to degrade within 5 s and their degradation saturated within 60 s. This behavior suggested that the PID was caused by positive charge accumulation in the front passivation films. Performing PID tests with a bias of −1500 V revealed that the degradation rate strongly depended on the applied bias whereas the saturation value was independent of the applied bias. Regeneration tests on degraded modules previously subjected to PID tests for durations of 5 and 10 min were performed by applying a positive bias of +1000 V. All the degraded modules completely recovered their performance losses within 60 s regardless of the degradation test duration. On the basis of these results, we proposed that these positive charges originate from positively charged K centers formed by extracting electrons from neutral and negatively charged K centers. This model readily explains the observed degradation and regeneration behavior. To test our model, we determined the fixed positive charge densities (Q f) of a silicon nitride passivation film before and after PID, for which it was found that Q f showed similar saturation behavior. Additionally, the saturated Q f value was of the same order as K center density. These results support our model involving a charging process of K centers.
科研通智能强力驱动
Strongly Powered by AbleSci AI