HgTe colloidal quantum dots based on diphenylphosphine precursor activation for infrared photodetectors

HgTe colloidal quantum dots (CQDs) are promising for infrared detection due to their broad spectral response, high photosensitivity, and potential for low-cost fabrication. However, conventional synthesis methods struggle to achieve precise size control, narrow size distribution, high monodispersity, and tetrahedral morphology. In this work, we introduce diphenylphosphine (DPP) to enhance the reactivity of the telluride precursor, promoting uniform nucleation and allowing precise control over CQDs morphology, size, and monodispersity. A dual regulation strategy based on synthesis temperature and thiol ligand alkyl chain length is further employed to enable controllable growth of CQDs in both size and shape. The organic-inorganic heterojunction short-wave infrared photodetector constructed using HgTe CQDs layers obtained via this method and an organic hole transport layer of PEDOT:PSS exhibits a responsivity of 652 mA/W at 1650 nm and a detection rate of 7.88 × 10 11 Jones at room temperature. This work presents a novel, cost-effective, and scalable strategy for synthesizing HgTe CQDs, laying a solid foundation for the development and commercialization of high-performance infrared photodetectors.