Self-Assembled Monolayer Hole-Selective Contact for Up-Scalable and Cost-Effective Inverted Perovskite Solar Cells

Abstract

Inverted positive-intrinsic-negative (p-i-n) perovskite solar cells (IPSCs) have attracted widespread attention due to their low fabrication temperature, good stability in ambient air, and the potential for use in flexible and tandem devices. In recent years, self-assembled monolayers (SAMs) have been investigated as a promising hole-selective contact for IPSCs, leading to an impressive record efficiency of about 26%, which is comparable to that of the regular n-i-p counterparts. This review focuses on the progress of SAM-based IPSCs from the perspective of energy level matching, defect passivation, interface carrier extraction, and SAMs’ stability improvement, as well as the advances in up-scalable fabrication of SAMs and perovskite layers for efficient solar modules and tandem devices. A cost analysis of the SAMs and other commonly used hole-selective materials is conducted to evaluate their cost-effectiveness for photovoltaic applications. Finally, the future challenges are pointed out and the perspectives on how to up-scale SAM-based IPSCs and improve their long-term operational stability are provided.