Exploring spatial resolution in high-sensitivity nanogap quantum dot photodetectors

Abstract

We propose a new approach to experimentally determine the spatial resolution of nanogap quantum dot (QD) photodetectors consist of solution-processed QDs. Cross talk between a pair of closely positioned QD photodetectors was measured. Devices with 200 nm spacing exhibit low crosstalk of 8.4%. A single QD photodetector also shows high sensitivity, with a lowest detectable optical intensity of 95.3 fW/μm2 achieved. The results show the potential of nanogap QD photodetectors for applications in high-density imaging/sensing arrays.