Dibenzo[b,d]thiophene Core Unit-Based Asymmetric Hole Transport Materials for Inverted Tin–Lead Perovskite Solar Cells

Three asymmetric hole transport materials (HTMs) based on dibenzo­[b,d]­thiophene core units have been rationally designed and synthesized for highly efficient inverted tin–lead perovskite solar cells (PSCs). The impact of asymmetric peripheral substituents on the photoelectrochemical properties of HTMs and the relationship between molecular configuration and their conversion performance are systematically investigated. Among these reported HTMs, HTM TPA-DBT-DTPA-based PSC exhibits a power conversion efficiency (PCE) of 22.4%, which is higher than the PEDOT:PSS-based control device, together with improved long-term stability.