Find in Library

The perovskite solar cell (PSC) as an emerging and promising type has been extensively studied. In this study, a model for a PSC prepared in ambient air was established by using SCAPS-1D. After that, it was further analyzed through varying the defect density of the perovskite absorber layer (N_t), the thin film thickness and energy-level matching between the electron transport layer (ETL), the perovskite absorber layer and the hole transport layer (HTL), for a better understanding of the carrier features. The N_t varied from 1.000 × 10¹¹ to 1.000 × 10¹⁷ cm⁻³. The performance of the solar cell is promoted with improved N_t. When N_t is at 1.000 × 10¹⁵ cm⁻³, the carrier diffusion length reaches μm, and the carrier lifetime comes to 200 nm. The thickness of the absorber layer was changed from 200 to 600 nm. It is shown that the absorber layer could be prepared thinner for reducing carrier recombination when at high N_t. The thickness effect of ETL and HTL is weakened, since N_t dominates the solar cell performance. The effect of the affinity of ETL (3.4–4.3 eV) and HTL (2.0–2.7 eV), together with three energy-level matching situations “ETL(4.2)+HTL(2.5)”, “ETL(4.0)+HTL(2.2)” and “ETL(4.0)+HTL(2.5)” on the performance of the solar cell were analyzed. It was found that the HTL with valence band 0.05 eV lower than that of the perovskite absorber layer could have a blocking effect that reduced carrier recombination. The effect of energy-level matching becomes more important with improved N_t. Energy-level matching between the ETL and perovskite absorber layer turns out counterbalance characteristic on J_sc and V_oc, and the “ETL(4.0)+HTL(2.5)” case can result in solar cell with J_sc of 27.58 mA/cm², V_oc of 1.0713 V, FF of 66.02% and efficiency of 19.51%. The findings would be very useful for fabricating high-efficiency and low-cost PSC by a large-scale ambient air route.