Decorating InSe Surface by Gold Species for Improved Carrier Transport and Efficient Sunlight Harvesting Toward High-Performance Flexible Photodetectors

摘要

Two-dimensional (2D) materials have aroused widespread interest due tothe high potential in modern photoelectronics. The strategy for improvingthe stability of 2D materials in the air, reinforcing formation, and transport ofphotoexcited carriers would open up promising routes toward flexible facilities.In this paper, surface engineering is executed on 2D InSe by decoratingAu species for a lower bandgap allowing for efficient sunlight harvestingand decreased barrier with the substrate for improved electron transport.Moreover, hot electrons produced by Au nanoparticles under light irradiationpour into InSe for boosting photocurrent. Au nanoparticles also serve as conductingbridges in InSe?Au photoanode, where the contact resistance is twoorders of magnitude lower than that of InSe electrode. Compared with InSeand other 2D counterparts, InSe?Au flexible photoelectrochemical detectorsbehave with outstanding performances under sunlight irradiation, includingresponsibility 55.4 μA W~(?1), detectivity 4.18 × 10~9 Jones. Importantly, theworking electrode shows excellent ON/OFF switching stability after bendingfor 5000 times (3 months of storage in the air). This surface engineeringprovides a general strategy to tailor 2D materials for wearable photoelectronicdevices in the future.