Regulating properties of Cu2ZnSn(S, Se)(4) absorber layer via the extra tiny Mg2+

Extra cation incorporations have been proved to enhance the properties of Cu2ZnSn(S, Se)(4) materials, and help to obtain high-efficiency solar cells. In this work, the authors study the influence of the extra tiny Mg2+ doping on the properties of Cu2ZnSn(S, Se)(4) films. Through tuning the amount of Mg into the precursor solution, the crystallization, morphology, light absorption, and electrical properties all have been improved and can reach the optimum at 3% Mg-doping, which is in favour of high-performance CZTSSe devices. The authors' finding also demonstrates Mg element can be regarded as the new candidate for extra cation incorporations.