One-Step Rapid Deposition of Bi2S3 Thin Film and Comprehensive Study of Its Photoelectrochemical Activity

Achieving the synthesis of bismuth sulfide (Bi2S3) thin films with high crystallinity and controllable morphology via simple and energy-saving deposition processes is highly desired. A novel, green, and open-air pressure solution-based deposition technique was developed to prepare horizontally orientated Bi2S3 thin films by applying less toxic and commercially available BiCl3 and thiourea as precursors. The deposition time was effectively shortened to the minute level via controlling the mixing mode of the precursors. The crystallinity and surface morphology of Bi2S3 were highly dependent on the synthesis temperatures. Bi2S3 thin films synthesized at a moderate temperature of 450 °C possessed a continuous surface with high crystallinity and exhibited superior photoelectrochemical performance with a high photocurrent density of 2.6 mA/cm2 at 0.6 V vs Ag/AgCl. The promising photoelectrochemical performance can be attributed to the high transfer efficiency of photogenerated electron–hole pairs owing to the small interfacial resistance and long lifetime of photogenerated carriers.