The CZTS, CZTSe and CZTSSe compounds are promising for use as an absorber in thin film solar cells (SC), especially given the relatively low cost of PV modules production based on them and widespread of elements in the earth's crust. In recent years the efficiency of SC based on them has increased significantly, however, it needs new innovative solutions for their sustainable competition with CIGS and CdTe. One of the way to overcome the limitations of recombination, to reduce the open circuit voltage deficit (V_oc) and to increase the kesterite-based devices efficiency is doping of thin films by cations of Ge.

The article includes a brief literature data review regarding recent trends in the development of research of semiconductor compounds based on kesterites with impurities of Ge atoms and devices based on them as well.