Development of Broadband PbS Quantum Dot/Graphene Photodetector Arrays with High-Speed Readout Circuits for Flexible Imagers

Colloidal quantum dot (QD)/graphene nanohybrid heterostructures provide a promising scheme for quantum sensors as they take advantage of the strong quantum confinement in QDs with enhanced light–matter interaction, spectral tunability, suppressed phonon scattering, and extraordinary charge mobility in graphene at room temperature. Herein, we report development of a flexible, nine-channel PbS QD/graphene nanohybrid imaging array on polyethylene terephthalate using a facile process for device fabrication, signal acquisition, and processing. The PbS QD/graphene imaging array exhibited high and uniform photoresponse. At a 1.0 V bias, the highest responsivity was 9.56 × 103–3.24 × 103 A/W for 400–1000 nm incident light [ultraviolet–visible–near-infrared (UV–vis–NIR)] with a power of 900 pW. In addition, the array has a consistent spectral response with bending down to a radius of curvature of a few millimeters. The demonstration of imaging at broadband wavelengths in the UV–vis–NIR range indicates that QD/graphene nanohybrids provide a viable approach for flexible photodetectors and imagers.