Study of the Growth Mechanism of Organic Chemical Bath-Synthesized PbS Thin Films at Atomic Resolution

As a crucial narrow bandgap semiconductor material, lead sulfide (PbS) has attracted significant research interest due to its numerous advantageous properties. In the conventional aqueous solution system for PbS growth, there are often problems, including high doping concentration and the existence of oxygen-related defects. In this study, PbS thin films were prepared by chemical bath deposition in a purely organic environment with a regular cubic morphology. Comprehensive transmission electron microscopy (TEM) techniques were employed for the structural characterization of the PbS nanocrystals. Cross-sectional structural characterization of the constituent seed layer and the growing films, in conjunction with systematic morphological analyses of the nanocrystals at sequential growing stages, provides insights into the possible growth mechanism underlying the morphological evolution of the PbS nanocrystals. These results would provide a viable solution for anaerobic growth of PbS thin films with various defect problems largely inhibited. It is expected that this work will further enhance the performance of related devices and promote their multifunctional applications in the future.