Chemical bath deposition-based synthesis of tin sulfide on silicon substrate and its application as a photodetector

Tin sulfide (SnS) is an attractive compound semiconductor for photovoltaic and sensing applications because of its abundance and non-toxicity. In the present work, the synthesis of SnS thin films on silicon substrates by chemical bath deposition (CBD) technique has been demonstrated. Tin chloride (SnCl₂.2H₂O) and thiourea were used as the tin and sulfur sources to deposit the SnS films with triethanolamine (TEA) as the complexing agent and sodium hydroxide (NaOH) as alkaline bath. To understand the growth mechanism, a time interrupted growth series was adopted at a temperature of 90 °C for different time durations i.e., 60 min, 120 min, and 180 min. A photosensor was fabricated using the SnS/Si heterojunction and its performance was investigated through electrical (current-voltage) and optical (photo-response) measurements. The I–V characteristics of the developed photodetector were recorded under dark and different light intensities. The device exhibited significant response to light even without a bias voltage.