Linear Variable PbS-DMSO Filter with Potentiality for Hyperspectral Imaging Applications

Under the synergistic effect of Mie scattering and dimethyl sulfoxide (DMSO) ligand modification, a novel linear variable PbS-DMSO filter obtained by regulating the quantity and spacing of PbS-DMSO nanoparticles exhibits continuous variable filtering capability in the wide spectral range of 500–1100 nm, with significant slope and cutoff depth of filtering. The surface modification of PbS quantum dots (QDs) with DMSO drastically enhances the light absorption, thereby increasing the cutoff depth and slope of filtering. Moreover, the modification of PbS QDs with DMSO also results in the aggregation of PbS QDs into nanoparticles with an average diameter of ∼100 nm, providing conditions for the generation of the Mie scattering effect. Based on the Mie scattering effect, by regulating the quantity and spacing of PbS-DMSO nanoparticles, not only can the absorption characteristics of PbS-DMSO nanoparticles be further enhanced to improve the cutoff depth and slope of filtering but also the absorption wavelength range can be well adjusted to achieve arbitrary adjustment of the filtering spectral range. Combined with an image sensor, the spectral reconstruction ability of the linear variable PbS-DMSO filter is further demonstrated, which provides a research idea for breaking through the limitation of the number of sampling points in traditional array QD filters.