Interfacial Modulation through Mixed‐Dimensional Heterostructures for Efficient and Hole Conductor‐Free Perovskite Solar Cells
Masaud Almalki, Mohammad Hayal Alotaibi, Anwar Q. Alanazi, Felix T. Eickemeyer, Sultan M. Alenzi, Yahya A. Alzahrani, Laura Piveteau, Ahmed Y. Alymani, Abdulrahman Albadri, Hamad Albrithen, Jovana V. Milić, Shaik M. Zakeeruddin, Hong Zhang, Michaël Grätzel
Abstract
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%.