Electrical transport properties of dip-coated nanocrystalline Cu2ZnSnS4 thin films

Abstract

Direct deposition of thin films from pure solution has emerged as a promising route for low-cost chalcogenide absorber materials for solar PV. Electrical transport properties of Cu-based multicomponent material are under investigation and are expected to have a strong impact on final device performance. In this study, we report nanocrystalline Cu2ZnSnS4 (CZTS) thin films dip-coated from methanolic ink. Temperature variation of electrical conductivity of these films was studied in dark and under light in the temperature range from 77 to 500 K to investigate the different mode of conduction. Analysis of data revealed that transport of holes in these films is dominated by either hopping in defect states or activated band conduction depending on the temperature range. The films were p-type and showed high carrier concentration (1019 cm−3). Films were found to be pure kesterite CZTS as confirmed by X-ray diffraction and Raman spectroscopy.