One more step to fast and efficient short-wavelength infrared photodetection

Ligand exchanges play a crucial role in development of high-quality colloidal quantum dot (CQD) solids for fast and sensitive short-wavelength infrared photodetection. Sargent et al. report a two-step ligand exchange route to tailor efficient passivation, remove unwanted organics, and enhance charge transport, leading to a CQD photodetector with an EQE > 80% at 1550 nm, a measured detectivity of 8 x 10(11) Jones, and a 10-ns response time.