Light-Induced Interfacial Charge Transport of In2O3/Reduced Graphene Oxide/Non-Conjugated Polymers in a Wide Range of the Light Spectrum

To increase the use of the near-infrared (NIR) light from In2O3, a nanocomposite of In2O3/reduced graphene oxide was synthesised. To improve adhesion to the substrates, a small amount of PVA (polyvinyl alcohol) was added to the nanocomposite. Results showed that adding an appropriate amount of PVA to the nanocomposite remarkably enhanced the ability to extract photogenerated carriers due to interface optimisation based on the grain boundary filling with PVA and charge tunnelling effects. The nanocomposites exhibited photoconductive switching responses from the visible light region to the near-infrared range. Meanwhile, the organic/inorganic hybrid coating on silk fibres exhibited mutual conversion of positive and negative photoconductivity, as well as electrical switching responses to applied strain. Furthermore, it was found that a photoelectric signal could still be determined with zero bias after the In2O3/reduced graphene oxide nanocomposite had been stored for over four years. This reflects that the nanocomposites have an internal electric field that promotes the transfer of photogenerated carriers and prevents the recombination of photogenerated electrons and holes. Similar results were also obtained by adding an appropriate amount of other non-conjugated polymers, such as dendrimers. Physical mechanisms are discussed. This study provides reference values for the development of multifunctional organic/inorganic hybrids integrating non-conjugated polymer components to enhance specific properties.