NREL’s Joseph M. Luther, Zhu Zonglong of City University of Hong Kong, and others: Co-deposition of hole-selective contact layers and perovskite layers enhances the processability of perovskite solar cells.

Simplifying the manufacturing process of renewable energy technologies is crucial for lowering barriers to commercialization. In this context, to enhance the manufacturability of perovskite solar cells (PSCs), Joseph M. Luther at NREL and Zonglong Zhu at City University of Hong Kong have reported a one-step solution-coating procedure in which the hole-selective contact layer and the perovskite light-absorbing layer form spontaneously, thereby enabling high-efficiency inverted PSCs. The authors observed that, during perovskite film processing, phosphonic or carboxylic acids incorporated into the perovskite precursor solution self-assemble on the indium tin oxide substrate. As the perovskite crystallizes, these molecules organize into a robust self-assembled monolayer that serves as an excellent hole-selective contact layer. This approach addresses the wettability challenges of perovskite solutions, streamlines device fabrication, and improves the manufacturability of PSCs. The resulting PSC devices with a p-i-n architecture exhibit a power conversion efficiency of 24.5% and retain more than 90% of their initial efficiency after 1,200 hours of continuous operation at the maximum power point. Moreover, the method is compatible with various self-assembled monolayer molecular systems, perovskite compositions, solvents, and processing techniques, demonstrating broad applicability.