Direct Photopatterning of Heavy-Metal-Free Colloidal Quantum Dot for Multispectral Infrared Photodetector

Colloidal quantum dots have been extensively explored in recent decades as alternatives to epitaxial semiconductors across various applications such as spectrometers, phototransistors, focal plane array imagers, lasers, light-emitting diodes, and photovoltaics. Their unique characteristics include size-adjustable optical properties and potential for low-cost, large-area fabrication. These attributes make quantum dots highly suitable for infrared applications, particularly in advancing high-resolution multispectral infrared imaging devices, which remain technologically demanding. In this study, we demonstrate a multispectral infrared photodetector through direct photopatterning of different types of quantum dot pixels. By UV-induced ligand crosslinking via selective illumination through a photomask, multispectral quantum dot pixels can be constructed, enabling facile photodetection of near-infrared and short-wave infrared wavelengths. Additionally, to meet environmental standards, silver-chalcogenide quantum dots in the near-infrared and short-wave infrared ranges are introduced to fabricate a high-resolution multispectral photodetector.