Multispectral Photodetectors Based on PbS Colloidal Quantum Dots

PbS colloidal quantum dots (CQDs) are attractive materials for the realization of simple, low-cost, high responsivity near-infrared photodetectors due to the large tunability of their optical properties together with their solution processability. In this work we propose multiple PbS CQD photoconductive devices with different spectral sensitivity realized on silicon substrates. We characterized the devices in terms of dark current, responsivity and response speed. Eventually, we discuss an algorithm for wavelength measurement of a quasi-monochromatic radiation based on linear combination of photocurrents from different photodetectors.