A study on optoelectronic performance of perovskite solar cell under different stress testing conditions

Since the inception of perovskites in the light absorbing region of solar cell, perovskite solar cell (PSC) have come a long way from a mere power conversion efficiency (PCE) of 3.8% in 2009 to 25.2% in 2019. The sudden growth in efficiency is riddled with instability issues caused by myriad extrinsic and intrinsic factors like moisture, heat, cell configuration etc., which would prove difficult for commercial scalability of the cells. Like other commercially established photovoltaic cells, PSCs have to pass certain stress tests before it can be deemed commercially viable. In the present study, we have focussed on three main types of stress testing on perovskite solar cells, 1) Damp heat test (i.e. solar cells were exposed to high humidity (RH>85%) and high temperature (85 °C) simultaneously, 2) Thermal stress (sudden increase and decrease in ambient temperature with a ramp rate of 65 °C/h) and 3) Outdoor aging under natural diurnal conditions for 504 h. Our results show that the PSCs are more susceptible to accelerated degradation under damp heat test due to the combined effect of heat and moisture retaining less than 1% of initial PCE. Under lower humidity levels, they managed to retain ~70% of initial PCE. Moreover, cells had ~37% of initial PCE towards 504 h of outdoor exposure. Temperature dependence on resistances of the cell was also studied under thermal stress conditions. Our results and analysis would be helpful for those interested in developing or designing a consensus on testing PSCs before paving its way for commercialization.