Investigating the performance of mixed cation mixed halide-based perovskite solar cells using various hole-transport materials by numerical simulation

Recent achievements in perovskite solar cells (PSCs) have led to the efficiency of perovskite solar cells about 25.6% but the instability of the device is still a major concern in this era. In this work, owing to the better stability and optical properties the mixed cation lead mixed halide perovskite, FA(0.85)Cs(0.15)Pb(I0.85Br0.15)(3) has been chosen as the absorber layer while SnO2 and Spiro-OMeTAD are employed as electron transport layer and hole transport layer (HTL). The numerical simulation of the device structure FTO/SnO2/FA(0.85)Cs(0.15)Pb(I0.85Br0.15)(3)/Spiro-OMeTAD/Au was carried out using SCAPS-1D software. The power conversion efficiency of PSC is 15.36% obtained which is close to the experimentally reported value. To improve the stability and performance of FA(0.85)Cs(0.15)Pb(I0.85Br0.15)(3) based PSC various organic and inorganic HTLs were employed in place of Spiro-OMeTAD as its oxidation causes instability in the device. Among all HTLs Cu2O (Cuprous oxide) outperformed others. Further Cu2O-HTL based device parameters like the thickness of Cu2O, thickness and defect density of absorber, series and shunt resistance were varied and studied to get their optimum values. As a result of this simulation, and improved PCE of 19.38% was achieved for optimized device structure FTO/SnO2/FA(0.85)Cs(0.15)Pb(I0.85Br0.15)(3)/Cu2O/Au. These results give the idea for further improvements in such devices.