Defect control in perovskite solar cells by interfacial engineering using iodobenzene diacetate

Abstract Numerous studies identify that charge-carrier nonradiative recombination of defects restrains the photovoltaic performance of the devices. Herein, a novel interfacial modifier iodobenzene diacetate (DAIB) is used to mitigate the defects and improve charge carrier transportation at the interface between the perovskite layer and hole transporting layer. The surface morphology and crystalline state of perovskite are observed, the photoelectrochemical characterizations of the perovskite films are investigated, and the reaction mechanism of DAIB and the energy band change of the perovskite films are estimated. It is indicated that the DAIB modification can reduce the defect and nonradiative recombination, hence the hole extraction ability is improved. Therefore, a planar perovskite photovoltaic device interfacial modified with DAIB generates a maximum power conversion efficiency (PCE) of 20.08%, and the pristine device obtains an efficiency of only 18.19%. This research demonstrates an efficient and low-cost strategy for generating high-performance perovskite solar cells.