Silver Chalcogenide Colloidal Semiconductor Nanocrystals for Shortwave Infrared Optoelectronic Applications
발표자
김영훈 (국민대학교)
연구책임자
김영훈 (국민대학교)
초록
내용
Ag2Te colloidal quantum dots (CQDs) are of great interest in shortwave infrared (SWIR) optoelectronic applications owing to their size-tunable bandgaps with high optical properties. We present a synthesis method for Ag2Te CQDs that controls their crystal size and bandgap through chemical reactivity. This involves controlling the concentration and type of ligands, as well as the precursor ratio. The rapid termination of the reaction in this method prevents Ag2Te CQD decomposition, yielding monodisperse CQDs with absorption and emission in the 1100−1600 nm range. We also present core/shell-type Ag2Te/Ag2S CQDs, which improve their chemical stability and optical properties including photoluminescence (PL) intensity. Consequently, the Ag2Te/Ag2S CQD-based SWIR photodetector exhibits a high external quantum efficiency of 8.4% and a specific detectivity of 1.1 × 1011 Jones at 1550 nm, with a fast response time of 38 ns.