Effects of bias voltage application and light soaking on the performance of flexible perovskite photovoltaic modules

Abstract

Precise and quick performance measurement and power rating of Perovskite photovoltaic devices such as Perovskite solar cells (PSCs) and modules (PSC modules) are essential for their industrialization. A major issue of their performance measurement is their gradual performance change under light soaking, which necessitates preconditioning by light soaking prior to measuring their stabilized performance such as the I–V curves. The present study investigated the preconditioning of flexible PSC modules. It was shown that application of forward bias voltage to the PSC modules in the dark for a short time of typically <10 min. improves the performance of the modules such as the maximum output power P_max, which is virtually the same effect as the light soaking. When a forward bias voltage was applied in the dark, increase in the performance parameters such as the maximum output power P_max was observed. It was found that the magnitude and rate of the increase were nearly the same as those of the light soaking at 1 kW/m², when the forward bias voltage equal to the open circuit voltage V_oc at the same irradiance was applied in the dark. The present results clarified that preconditioning without light soaking is possible, and showed that the photo-generate voltage rather than the light itself plays an important role in the increase in P_max by the light soaking. It also offered the possibility to improve the productivity of the performance measurement of PSC modules.