Efficient and Less-Toxic Indium-Doped MAPbI₃ Perovskite Solar Cells Prepared by Metal Alloying Technique

Perovskite materials with ABX(3) structure (A: organic, B: metal, and X: halides) have attracted tremendous attention due to their outstanding optoelectronic properties. Herein, a novel approach is developed using chemical vapor deposition (CVD), i.e., metal alloying of halide-perovskite domain via ion-transfer (MAHDI) for the growth of high-quality perovskite films, grown directly from a metal precursor. This technique easily enables us to replace the toxic Pb metal (B site) with other metals using alloying approach. Using the proposed approach, we fabricated stable and efficient Pb-In perovskite solar cells (PSCs) with a maximum power conversion efficiency (PCE) of 21.2%, which is more efficient than the pure Pb-based PSCs (19.23%). Our characterization results reveal that In-doping improves the crystallinity and photoluminescence (PL) of the perovskite film, resulting in higher photovoltaic properties in the device. To demonstrate the potential of our proposed method for other alloys, we also fabricated PSCs based on Pb-25%Sn alloy and obtained PCE of up to 15.2%. Overall, MAHDI technique opens up a new direction in the field of perovskite devices demonstrating great advantages such as lower price, higher performance, scalability, and fabrication flexibility.