Interfacial Modulation through Mixed-Dimensional Heterostructures for Efficient and Hole Conductor-Free Perovskite Solar Cells

Abstract

Perovskite solar cells have led the new surge of solar energy research. However, their instability is a pressing issue mostly attributed to the perovskite interface with charge-selective transport layers. In this work, diethylammonium iodide (DEAI) surface treatment is used to mitigate interfacial non-radiative recombination losses by forming a mixed phase of layered perovskite on the surface. This results in enhanced device performance with the power conversion efficiency of 23.3% and improved operational stability under thermal stress. Moreover, the DEAI treatment facilitates interfacial hole transfer, enabling a carbon-based hole transport layer-free perovskite solar cell with a power conversion efficiency of 15.6%.