Mercury Chalcogenide Nanoplateleta??Quantum Dot Heterostructures as a New Class of Continuously Tunable Bright Shortwave Infrared Emitters

摘要： Despite broad applications in imaging, energy conversion and telecommunications, there are few nanoscale moieties that emit light efficiently in the shortwave infrared (SWIR, 1000-2000 nm or 1.24-0.62 eV). We report quantum confined mercury chalcogenide (HgX, X=Se, Te) nanoplatelets (NPLs) can be induced to emit bright (QY >30%) and tunable (900-1500+ nm) infrared emission from attached quantum dot (QD) “defect” states. We demonstrate near unity energy transfer from NPL to these QDs, which completely quench NPL emission and emit with high QY through the SWIR. This QD defect emission is kinetically tunable, enabling controlled mid-gap emission from NPLs. Spectrally resolved photoluminescence demonstrates energy dependent lifetimes, with radiative rates 10-20 times faster than their PbX analogs in the same spectral window. Coupled with their high quantum yield, mid-gap emission HgX dots on HgX NPLs provides a potential platform for novel optoelectronics in the SWIR.