CdS nanobelt-based self-powered flexible photodetectors with high photosensitivity

Abstract

Asymmetric contacts were used to assemble extremely photosensitive and self-powered photodetectors (SPDs) on rigid and polyimide (PI) substrates based on one-dimensional (1D)-CdS nanobelts. The photoresponse characteristics of the constructed devices were outstanding, including high photosensitivity (1.54 × 10⁶%), specific detectivity (2.36 × 10¹² Jones), responsivity (36 mA W⁻¹) and noise equivalent power (2.94 × 10⁻¹⁵ W Hz^−1/2) with 215 μW cm⁻² light irradiation, as well as having high reproducibility, environmental stability and speedy response of less than 30 ms. Flexible self-powered photodetectors (FSPDs) were also constructed on PI substrates, which had comparable photoresponse performance to the rigid one. Additionally, the as-fabricated FSPDs showed excellent folding endurance, electrical and mechanical flexural stability. Our findings suggest that the asymmetric contact device design used in this study is appropriate for high-performance FSPDs, particularly ultrafast nanodevices.