Efficiency Improvement of Bournonite CuPbSbS₃ Solar Cells via Crystallinity Enhancement

CuPbSbS₃ (bournonite) has emerged as a promising light-absorbing material for thin-film solar cells due to its attractive photophysical properties. The crystallinity of CuPbSbS₃ films is a main challenge of achieving high power conversion efficiency. Herein, we perform a series of optimization strategies to enhance the crystallinity of CuPbSbS₃ films, including adjusting the annealing temperature and reducing the carbon residue. The optimized CuPbSbS₃ film acquires an enhanced crystallinity, and an optimal solar cell device based on it achieves a power conversion efficiency of 2.65% with good stability. This efficiency is the highest value for CuPbSbS₃ solar cells up to now.