High performance self-powered UV-visible photodetectors based on TiO2/graphene/ZnIn2S4/electrolyte heterojunctions

TiO2 nanorods (TNRs)/graphene (G)/ZnIn2S4 (ZIS)/electrolyte heterojunction arrays were synthesized via a three-step synthesis method and applied as an ultraviolet (UV)-visible self-powered photodetector (SPPD). At zero bias, the SPPD exhibited high responsivities of 13.79 mA/W for UV light and 0.39 mA/W for visible light, respectively. Under UV irradiation, the SPPD showed a short rise time of 5 ms and a decay time of 10 ms. TNRs offered an effective pathway for electron transport, and the type-II energy band structure formed by ZIS stacking improved the response of TNRs to UV and visible light significantly. Furthermore, the graphene intermediate layer accelerated the separation and transfer of carriers due to excellent charge collection ability. Therefore, the TNRs/G/ZIS/electrolyte heterojunction arrays have great potential for application in UV-visible SPPD.

Automated summary

TiO2 nanorods/graphene/ZnIn2S4/electrolyte heterojunction arrays were successfully synthesized via a three-step method and applied as a high-sensitivity UV-visible self-powered photodetector (SPPD). TNRs provided an effective pathway for electron transport, while the type-II energy band structure formed by ZIS stacking significantly improved the response to UV and visible light. The graphene intermediate layer accelerated the separation and transfer of carriers.