How different are CZTS grain boundaries ?

No, defects are not always bad. Vacancies, antisites, or impurities are in general trapped at the grain boundaries and contribute to scattering (of charge carriers). In general, grain boundaries reduce the performance (efficiency of the solar cell). However, there are certain materials where the defects enhance performance. CdTe, CuInSe2 (CIS), Cu2ZnSnS4 (CZTS) are a few examples. The present work involves CAFM studies on CZTS films deposited to Si and soda-lime glass substrate to explore the underlying physics behind unique grain boundary physics in CZTS. Discussions are made in the light of the reactions that take place on CZTS surface and corresponding energy band diagrams are drawn