Tunability of the photoelectric properties of CdSe thin films through doping with manganese toward photovoltaic applications

Tandem solar cells have been demonstrated to surpass the Shockley-Queisser limit, promising the transition to third-generation solar cell technology. Tandem solar cells comprise thin film layers of various band gap semiconductors, and CdSe is a promising candidate for the top cell. In this study, we explore the properties of thermally evaporated CdSe thin films doped with 0 to 5 wt% Mn and report a significant five-fold increase in carrier concentration. Furthermore, our optoelectrical studies indicate a band gap energy of 1.681eV, experiencing up to a 28 meV shift with 5 wt% Mn doping and identifies 1 wt% as the optimal doping concentration, offering the best electrical properties and photo-response while maintaining a stable band gap.