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.