Ultrasound-modulated microstructure of PbS film in ammonia-free chemical bath deposition

In this work, ultrasound was used as an efficient way to solve the non-uniform nucleation over large-scale substrate and to modulate film microstructure for performance improvement. Lead sulfide (PbS), as one of the most important IV-VI group semiconductors, was employed to prepare large-scale uniform films with the assistance of ultrasound in ammonia-free chemical bath deposition (CBD). The characteristics of PbS films, including crystalline structure, stoichiometry, surface morphology, cross-section structure, thickness, roughness and optical property were studied to reveal the modulating effect of ultrasound. In addition, the growth mechanism of PbS films was discussed. More importantly, PbS films prepared by ultrasound-assisted ammonia-free CBD provided better photoelectrochemical (PEC) performance with intense photosensitivity.