Improvement of the performance of Cu2ZnSn(S,Se)4 solar cells by annealing Li-doped Cu2ZnSnS4 precursor films in air

The PCE of the CZTSSe solar cell was enhanced from 9.06% to 10.21% by optimizing the Li doping content, and then further increased from 10.21% to 11.13% by adjusting the annealing temperature and time of CZTS doped with the optimal Li content in air.