A Near-Infrared Miniature Quantum Dot Spectrometer

The acquisition of near-infrared (NIR) spectral information is most notably accessed in the scientific analysis and industrial technology. With the development of artificial intelligence technology, miniature NIR spectrometers are usually required to realize compact equipment. Quantum dot spectrometer is demonstrated to be a promising reconstructive spectrometer; however, the spectral range is limited in the visible range due to the lack of high-resolution NIR detectors and quantum dot filters. In this work, a NIR quantum dot spectrometer is constructed by integrating 195 finely spectra-tunable PbS and PbSe based NIR quantum dots as filters and a NIR complementary metal-oxide semiconductor as detector. The spectra-tunable PbS and PbSe quantum dots are achieved by controlling the key parameters of colloidal synthesis, ligand exchange, and cation exchange. Combined with the compressive-sensing based total-variation algorithm, the NIR quantum dot spectrometer reaches an average spectral resolution of 6 nm in the wide spectral range of 900–1700 nm, showing the bright prospect in developing compact NIR spectrometer for artificial intelligence technology.