Polymer-Gel-Derived PbS/C Composite Nanosheets and Their Photoelectronic Response Properties Studies in the NIR

Abstract

Non-conjugated polymer-derived functional nanocomposites are one of the important ways to develop multifunctional hybrids. By increasing the degree of crosslinking, their photophysical properties can be improved. PbS is a class of narrow bandgap infrared active materials. To avoid aggregation and passivation of the surface defects of PbS nanomaterials, a large number of organic and inorganic ligands are usually used. In this study, PbS/C composite nanosheets were synthesized with Pb2+ ion-crosslinked sodium alginate gel by one-pot carbonization. The resulting nanosheets were coated on untreated A4 printing paper, and the electrodes were the graphite electrodes with 5B pencil drawings. The photocurrent signals of the products were measured using typical 650, 808, 980, and 1064 nm light sources. The results showed that the photocurrent switching signals were effectively extracted in the visible and near-infrared regions, which was attributed to the mutual passivation of defects during the in situ preparation of PbS and carbon nanomaterials. At the same time, the resulting nanocomposite exhibited electrical switching responses to the applied strain to a certain extent. The photophysical and defect passivation mechanisms were discussed based on the aggregation state of the carbon hybrid and the interfacial electron interaction. This material would have potential applications in broadband flexible photodetectors, tentacle sensors, or light harvesting interdisciplinary areas. This study provided a facile approach to prepare a low-cost hybrid with external stimulus response and multifunctionality. These results show that the interfacial charge transfer is the direct experimental evidence of interfacial interaction, and the regulation of interfacial interaction can improve the physical and chemical properties of nanocomposites, which can meet the interdisciplinary application. The interdisciplinary and application of more non-conjugated polymer systems in some frontier areas will be expanded upon.