Upgraded antisolvent engineering enables 2D@3D quasi core-shell perovskite for achieving stable and 21.6% efficiency solar cells

Abstract

Perovskite solar cells (PSCs) have become a promising alternative to sustainable energy due to their high power conversion efficiency (PCE) and low-cost processing. However, the practical applications of PSCs are still limited by the trade-off between high performance and poor stability under operation. Here, a 2D@3D perovskite with quasi core-shell architecture linking the superiorities of both two-dimensional (2D) and three-dimensional (3D) perovskite is prepared through a novel upgraded antisolvent approach. The basic properties as well as the phase distribution and the charge transport behavior of the 2D@3D perovskite were systematically elucidated. A high PCE of 21.60% for 2D@3D PSCs is achieved due to the enhanced surface and grain boundaries passivation, improved energy level alignment and efficient holes transport. The 2D@3D perovskite device without encapsulation shows significantly improved stability at the room temperature (90% of initial PCE for 45 d with a relative humidity of 50%±5%) and relative thermal conditions (83% of initial PCE for 200 h under 85 °C). Compared with traditional 3D PSCs, it proved that such 2D@3D perovskite configuration is an effective architecture for enhancing efficiency and improving stability and therefore will facilitate the further industrialization of PSCs.