Development of sprayed CuInS2thin film absorber for nanostructured solar cell

Abstract

ABSTRACTCuInS2(CIS) films were prepared by chemical spray pyrolysis (CSP) method in air using CuCl2, InCl3and SC(NH2)2as precursor materials. The effect of the absorber growth temperature in the interval of 240-350 °C and precursors’ molar ratio in the spray solution on the CIS film properties and ZnO/In2S3/CIS-type CSP-deposited thin film solar cell output characteristics has been studied. CIS films were characterized by XRD and EDX, solar cells were characterized by IV curves in dark and under illumination, and junction barrier height (Φb). The highest Φbof 1170 meV and open circuit voltage (Voc) of 560 mV were recorded for the cell with CIS absorber grown at 250 °C. Increasing the CIS deposition temperature decreases Φband Voc, makes a component of solar cell photosensitive and increases current density. The precursors’ molar ratio in spray solution becomes relevant at CIS growth temperatures higher than 300 °C as deposition of thiourea-rich solutions suppresses oxide formation in CIS layer and contributes to higher open circuit voltage.