Nanostructured Heterojunction Solar Cells Based on Pb₂SbS₂I₃: Linking Lead Halide Perovskites and Metal Chalcogenides

The quaternary chalcogeno-iodides Pb2SbS2I3, comprising group IV and V elements, has attracted significant attention because of its unique semiconducting and ferroelectric properties. However, it has not yet been applied in solar cells. Herein, we report the first fabrication of nanostructured solar cells using Pb2SbS2I3 as a light harvester, prepared through a reaction between antimony sulfide, deposited by chemical bath deposition on mesoporous (mp)-TiO2, and lead iodide under an Ar atmosphere at 300 °C. A power conversion efficiency (PCE) of 3.12% under the standard illumination conditions of 100 mW/cm2 was achieved for the Pb2SbS2I3 layer sandwiched between mp-TiO2 and an organic hole conductor. Pb2SbS2I3 cells without encapsulation show good humidity stability over 30 days, retaining about 90% of the initial performance.