Microencapsulated Perovskite Crystals via In-Situ Permeation Growth from Polymer Microencapsulation-Expansion-Contraction Strategy: Advancing A Record Long-Term Stability Beyond 10,000 Hours for Perovskite Solar Cells.

Organic metal halide perovskite solar cells (PSCs) bearing both high efficiency and durability were predominantly challenged by inadequate crystallinity of perovskite. Herein, a polymer microencapsulation-expansion-contraction (MEC) strategy was proposed for the first time to optimize the crystallization behavior of perovskite, typically by adeptly harnessing the swelling and deswelling characteristics of poly(4-Acrylamidopyridine) (poly(4-AcM)) network on PbI 2 surface. It can effectively retard the crystallization rate of perovskite, permitting meliorative crystallinity featured by increased grain size from 0.74 to 1.32 μm and reduced trap density from 1.12 × 10 16 to 2.56 × 10 15 cm -3 . Moverover, profiting from the protection of poly(4-AcM) microencapsulation layer, the degradation of the perovskite was markedly suppressed. Resultant PSCs gained a robust power conversion effiency (PCE) of 24.04%. Typically, they maintained 91% of their initial PCE for 13,008 hours in a desiccated ambient environment and retained 92% PCE after storage for 4,000 hours with a relative humidity of 50±10%, which is the state-of-the-art long-term stability among the reported contributions. This article is protected by copyright. All rights reserved.