Interface Modification via Rare Earth Material to Assist Hole Migration for Efficiency and Stability Promotion of Perovskite Solar Cells

Abstract

Interface defect is limiting factors of the charge dynamics and stability of perovskite solar cells (PSCs). Herein, a rare earth metal oxide cerium oxide (CeO2) is introduced into the interface between perovskite and spiro‐OMeTAD [2,2,7,7‐tetrakis (N, N ‐di‐p‐methoxyphenyl‐amine) 9,9‐spirobifluorene] to passivate interfacial defects. Due to the nearest‐neighbor interaction of CeO2 with spiro‐OMeTAD, it could accelerate the oxidization process of spiro‐OMeTAD to form a donor‐acceptor complex at this interface, which can overcome the interface barrier for the high hole collecting ability. The bonding formation between lead and oxygen makes this heterojunction emerge a metal conduction behavior at this interface. With the insertion of CeO2 between perovskite and spiro‐OMeTAD, which can improve hole‐transferring to balance the extraction of electron and hole by their respective electrodes, for the decreased device hysteresis with the higher efficiency and improved stability. The results show that the CeO2 based PSCs device achieve a power conversion efficiency (PCE) of over 24% with remaining more than 87% of the initial PCE after 2570 hours of storage at 20∽30% humidity.This article is protected by copyright. All rights reserved.