Crystallization Regulation and Defect Passivation of High‐Performance Flexible Perovskite Light‐Emitting Diodes Based on Novel Dielectric/Metal/Dielectric Transparent Electrodes

Abstract Perovskite materials are considered as potential materials suitable for flexible wearable displays due to their excellent optoelectronic properties and flexibility. However, the brittleness of conventional ITO electrodes, as well as the poor crystallization of perovskite on flexible substrates, have hindered the development in flexible perovskite light‐emitting diodes (PeLEDs). Herein, a flexible PeLED based on a novel transparent electrode WO 3 /Au/WO 3 (WAW), combined with the adjustment method of incorporation of polymer [polyethylene oxide‐polypropylene oxide‐polyethylene oxide triblock copolymer (P123)], is proposed to assist crystallization and defect passivation. The strong anchoring effect between P123 and perovskite accelerates the nucleation and crystallization process of perovskite films based on flexible substrates (shortened from 10 min to 1 min), induces the formation of uniform and small‐sized perovskite grains, and passivates non‐radiation defects caused by poor crystal quality. As a result, a high‐performance green PeLED with a maximum external quantum efficiency (EQE) of 14.45% is obtained. The corresponding flexible PeLED displays a maximum EQE of 11.9%, and it can keep a 96.5% original current efficiency after bending for 1000 cycles. This work will provide feasible guidance for the design and manufacture of high‐performance flexible all‐inorganic PeLEDs.