Abstract
Abstract
Solution-processed short-wave infrared (SWIR) photodetectors utilizing colloidal quantum dots (QDs) represent a transformative advancement in next-generation infrared optoelectronics. Although environmentally benign silver telluride (Ag2Te) QDs have shown promise for SWIR detection, the performance of such devices, especially beyond 1.5 μm, remains constrained by inadequate energy-level alignment at heterojunctions and insufficient passivation of interfacial defects. This study introduces an inorganic bismuth chloride (BiCl3) interlayer between the SnO2 electron transport layer and the Ag2Te QD active layer. This modification simultaneously facilitates effective defect passivation and optimized band alignment, leading to a significant improvement in photocarrier collection efficiency. The resulting BiCl3-modified Ag2Te QD photodiodes achieve a record external quantum efficiency (EQE) of approximately 20% at 1540 nm under zero bias, along with a specific detectivity (D*) of 2.3 × 1011 Jones at room temperature. This work provides valuable insights into interface engineering for developing high-performance eco-friendly SWIR QD optoelectronic devices.