Uncooled and Broadband PbSe Colloidal-Quantum-Dot Short-Wave Infrared Photodetectors

Solution-processed PbSe colloidal quantum dots (CQDs) are promising candidates for building high-performance infrared photodetectors due to their widely tunable band gaps and high carrier mobility. However, the development of PbSe CQD photodetectors has been hampered by their poor electronic properties. In this work, a monomer-assisted ligand exchange (MLE) strategy was developed that leads to PbSe CQDs with improved electronic properties including increased carrier mobility, extended carrier lifetime, and enhanced electronic uniformity. Based on the MLE approach, short-wave infrared photodetectors with a record specific detectivity (D*) of 3.1 × 1012 Jones at 1640 nm and their first 300000-pixel focal plane arrays were demonstrated. In addition, uncooled and broadband PbSe CQD photodetectors─showing photoresponses of up to 2.5 μm─were achieved. Notably, a room-temperature D* of 3.0 × 1011 Jones was achieved at a wavelength of ∼2360 nm, exceeding that of uncooled InGaAs photodetectors at similar wavelengths.