Characterization of a co-evaporated Cu2SnS3 thin-film solar cell

Abstract

Cu2SnS3 (CTS) absorber layer was deposited onto a Mo-coated soda-lime glass substrate by sulfurizing a coevaporated Cu-SnS precursor thin film. Phase composition and quality of the layer were examined by X-ray diffraction, Raman spectroscopy and scanning electron microscopy. A solar cell with such CTS absorber layer was characterized by current-voltage, external quantum efficiency, capacitance-voltage, and admittance spectroscopy. The CTS solar cell exhibited a maximum conversion efficiency of 2.01%. Capacitance-voltage measurement showed that CTS absorber had hole carrier concentration of 6.37 x 10(16) cm(-3) and depletion width of 82 nm at room temperature. Admittance spectroscopy showed capacitance steps that might have originated from a deep-level with activation energy and pre-exponential factor of about 0.11 eV and 8.31 x 10(4) s(-1)K(-2), respectively. The concentration of the deep-level defects was estimated to be 5.23 x 10(18) cm(-3).