| Abstract Scope |
The progress in all-perovskite tandem solar cells (TSCs) is limited by the performance of low-bandgap tin-lead (Sn-Pb) perovskite solar cells (PSCs). Furthermore, the efficiency and stability of Sn-Pb PSCs are frequently restricted by the utilization of the traditional poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) (PEDOT:PSS) hole transport layer (HTL). In this work, we select an economically feasible and cost-effective modification material as both an interface bridge and an additive of perovskite precursor solution to fabricate efficient HTL-free Sn-Pb PSCs. The introduction of this material can promote perovskite heterogeneous nucleation, improve carrier transport, suppress the oxidation of Sn2+ to Sn4+ and have better energy level alignment. Consequently, the best-performing Sn-Pb PSC achieved the highest PCE of more than 22.8%, which enabled efficient all-perovskite TSCs with a maximum PCE of more than 27.5%. This work provides a novel perspective for fabricating efficient perovskite devices with a simplified structure. |