(276f) Mid-IR Ag2se-Based Colloidal Quantum Dot Photodetectors

Mid-wavelength infrared (IR) photons have high penetration through airborne obscurants such as fog and mists, rendering mid-IR photodetectors ideal for use in long-distance thermal sensing and enhanced night vision applications. Colloidal quantum dot-based mid-IR photodetectors present a promising path toward fabricating sensors and imagers at significantly reduced cost compared to state-of-the-art epitaxial grown quantum-well IR detectors. Herein, we report on recently discovered silver chalcogenide quantum dots that exhibit distinct optical absorption in the mid-IR. These colloidal quantum dots demonstrate a narrow bandgap metastable tetragonal phase, not available in bulk, and contain excess electrons, allowing intraband optical transitions between the first and the second conduction energy levels. In this presentation, we will present the synthesis, characterization, and photoconductive photodetector device characteristics of this relatively benign colloidal IR material, in contrast to highly toxic Hg-based competing mid-IR devices.