Fabrication of PbSe quantum dot based flexible photodetector device arrays

Near-infrared spectroscopic detection has attracted great attention due to its extensive applications in various fields. Colloidal quantum dots exhibit significant potential for flexible and large-scale manufacturing, owing to their distinctive optoelectronic properties and versatile preparation methods. The present work investigates the synthesis of PbSe colloidal quantum dots via the thermal injection method and their application in the fabrication of photoconductive detector arrays. The effect of two different short-chain ligands [1, 2-ethanedithiol (EDT) and tetrabutylammonium iodide] on infrared detector performance is investigated, and it is found that EDT is better for improving device performance. Large-area electrode arrays were fabricated on flexible polyethylene terephthalate substrates using an inkjet deposition process. The cut-off wavelength of this detector is 0.71 eV, exhibiting excellent optical response in the visible-near-infrared range. The devices achieve a sensitivity of 9 A/W and a normalized detectivity of 6.5 × 1012 Jones under illumination from a 1550 nm laser light source. This study underscores the potential of PbSe quantum dots for advanced large-area photodetector arrays in infrared detection.