Influence of Al doping in zinc oxide electron transport layer for the degradation triple-cation-based organometal halide perovskite solar cells

Abstract

Various strategies have been adapted to fabricate stable organic-inorganic hybrid perovskite (PVT) solar cells (PSCs). The triple-cation (CH3NH3+ (MA+), CH3(NH2)2+ (FA+), and Cs+) along with dual-anion (I− and Br−)-based PVT (TC-PVT) layer offers better stability than single cation-based PVTs. The deprivation of the PVT absorber is also influenced by the interface of the absorber with the charge transport layer (electron transport layer (ETL) and hole transport layer (HTL)). Here, the degradation of the TC-PVT coated on Al-doped zinc oxide (AZO) as well as FTO/AZO/TC-PVT/HTL structured PSC was examined for various Al to Zn molar ratio (RAl/Zn) of AZO. The PL decay study of FTO/AZO/TC-PVT revealed that the lowest degradation in the power (35.38%) was observed for the AZO with RAl/Zn of 5%. Furthermore, the PV cell parameters of the PSCs were analytically determined to explore the losses in the PSCs during degradation. The shunt resistance reduction was maximum (50.32%) for RAl/Zn = 10%, whereas, minimum shunt loss (7.33%) for RAl/Zn of 2%. The highest loss due to series resistance was observed for RAl/Zn of 0%. The changes in diode ideality factor (n) and reverse saturation current density (J0) were the smallest for RAl/Znof 10%.