Enhancing solar cell efficiency through tandem structures utilizing lead-free mixed cation perovskites and CZTSe absorber layers oleh Rasmiah S. Almufarij, M. Jamil, Emaan Alsubhe, S.M. Alghamdi, Elsammani Ali Shokralla, Khushi Muhammad Khan, Arslan Ashfaq, Adnan Ali, Syed Asfar Ahmad Jafri, Mohd Shakir Khan