Synthesis and characterization of sulfate precursor based SnS thin films using SILAR technique at elevated solution temperature

Abstract

In this study, a microprocessor-controlled SILAR technique was used to prepare SnS thin films on glass substrates using equimolar SnSO4 and Na2S precursors. The combination of sulfate precursor and increase in the solution temperature lead to the dilution of phase purity. The effects of these heterogeneous phase blend on the structural, optical, electrical and photo-response properties of the films were studied in detail. The coexistence of the SnS and SnO2 phases was confirmed by XRD and Raman analysis. The energy band structure of the films was significantly affected by the presence of SnO2. The optical band gap of the films shifted from the mid-visible to the UV region of the electromagnetic spectrum as the amount of mixed phases in the films increased. The photoluminescence spectra also showed prominent emission in the blue and green regions arising from the phase coexistence. Marginal increase in the electrical conductivity was observed for higher solution temperature. The rise-time of the photocurrent was found to increase significantly (nearly 80 %) owing to the presence of heterogenous phase blend. This prolonged decay time suggests the possibility of persistent photoconductivity (PPC) in the films. Data availability statementThe data cannot be made available at this point as the results presented here are part of ongoing research work.