Effect of a SiO2 film on the potential-induced degradation of n-type front-emitter crystalline Si photovoltaic modules. (29th November 2019)

• Record Type: Journal Article
• Authors: Suzuki, Tomoyasu; Yamaguchi, Seira; Nakamura, Kyotaro; Masuda, Atsushi; Ohdaira, Keisuke
• Is Part Of: Japanese journal of applied physics. Volume 59:Number SC(2020)
• Publication Date: 2019-11-29
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/1347-4065/ab4cf9
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We investigated the effect of silicon dioxide (SiO2 ) film in n-type front-emitter (n-FE) crystalline Si solar cells on the potential-induced degradation (PID) of n-FE photovoltaic modules. After PID tests by applying a bias of −1000 V at 85 °C for a few min, the modules with the cells without SiO2 did not degrade in the short-circuit current density and the open-circuit voltage ( V oc ). Since the degradation is known to be due to positive charge accumulation in SiN x films, the result suggests that such SiO2 acts as barriers to retain accumulated positive charges. After further PID tests, modules without SiO2 show faster and more significant degradation by a decreases in the fill factor (FF) and the V oc . It has been proposed that the degradation in the FF and V oc is caused by sodium (Na) introduction into cells. The results therefore suggest that SiO2 delays Na migration.