CuFeSe2 Quantum-Dot Based Infrared Photodetectors with Functionality in the Ambient

Applications such as infrared cameras and detectors have driven efforts to discover novel infrared materials. Quantum dots have been demonstrated as sensitive and tunable infrared absorbers. Most successful quantum dots are prepared from heavier II-VI materials based on mercury and therefore pose toxicity hazards. Here we investigate CuFeSe 2 quantum dots as a potential solution processed, minimally hazardous photodetector material for the fabrication of devices with functionality in the ambient. Following characterization of the nanocrystals through Transmission Electron Microscopy (TEM) and their absorption spectrum with infrared spectroscopy, we demonstrate infrared and visible light detection with two device architectures. A Metal-Semiconductor-Metal (MSM) photoconductor shows optoelectronic response with infrared light, and a p-n heterojunction shows the characteristic I-V curve with a broadband visible-infrared light source. We thus demonstrate the application of CuFeSe 2 quantum dots as an infrared active material, and its heterojunction with silicon as a promising photodetector device.