How antisolvent miscibility affects perovskite film wrinkling and photovoltaic properties.

ABSTRACT: Charge carriers' density, their lifetime, mobility, and the existence of trap states are strongly affected by the microscopic morphologies of perovskite films, and have a direct influence on the photovoltaic performance. Here, we report on micro-wrinkled perovskite layers to enhance photocarrier transport performances. By utilizing temperature-dependent miscibility of dimethyl sulfoxide with diethyl ether, the geometry of the microscopic wrinkles of the perovskite films are controlled. Wrinkling is pronounced as temperature of diethyl ether (T_DE) decreases due to the compressive stress relaxation of the thin rigid film-capped viscoelastic layer. Time-correlated single-photon counting reveals longer carrier lifetime at the hill sites than at the valley sites. The wrinkled morphology formed at T_DE = 5 °C shows higher power conversion efficiency (PCE) and better stability than the flat one formed at T_DE = 30 °C. Interfacial and additive engineering improve further PCE to 23.02%. This study provides important insight into correlation between lattice strain and carrier properties in perovskite photovoltaics.

SUBMITTER: Kim SG 

PROVIDER: S-EPMC7946869 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature