Solution‐Processable Zinc Oxide for Printed Photovoltaics: Progress, Challenges, and Prospect

Abstract

Zinc oxide (ZnO) is a promising candidate as the electron‐transporting layer of roll‐to‐roll printed organic and perovskite solar cells (OSCs and PVSCs) because it is low cost, nontoxic, earth‐abundant, and has multiple solution‐processable routes comparable. It has been widely used in both OSCs and PVSCs for many years. With the long‐time development of the ZnO buffer layer, various synthesis, fabrication, and modification approaches have been developed. Meanwhile, several issues including light‐soaking issues, defects issues, and agglomeration issues have emerged and have been solved. In this review, the synthesis approaches of solution‐processed zinc oxide, the application in the OSCs and the PVSCs, and the typical challenges of the solution‐processed ZnO for use in the OSCs and PVSCs have been summarized. Finally, an outlook on the development of solution‐processed ZnO for the upscaling of OSCs and PVSCs is given.