Boosting the Electrical Properties of Cu2ZnSn(S,Se)4 Solar Cells via Low Amounts of Mg Substituting Zn

Substitution of Zn with Mg has been reported to suppress CuZn defects, which can improve the photoelectric performance of Cu2ZnSn(S,Se)4 (CZTSSe) photovoltaic devices. In our work, the electrical property enhancement of an absorbing layer can be found by incorporating Mg content into the as-prepared precursor solution, forming an alloyed Cu2MgxZn1-xSn(S,Se)4 (CMZTSSe) phase and increasing the photoelectric performance of devices. By adjusting the doping ratio of Mg, we systemically study the impact of Mg content on the crystal structure, thickness, and electrical properties of the Cu2MgxZn1-xSn(S,Se)4 absorbing layer. Also, the photoelectric performance of Cu2MgxZn1-xSn(S,Se)4 solar cells have a large improvement, and the optimal photoelectric conversion efficiency (PCE) of 7.76% for devices is obtained. Our results offer the finding that Mg doping can optimize the electrical properties of Cu2ZnSn(S,Se)4 photovoltaic devices.