PHOTOSENSITIVITY OF PbS COLLOIDAL QUANTUM DOTS BASED NANOSTRUCTURES WITH AN ENERGY BARRIER

Abstract

A new architecture of photosensitive elements for the near (0.7–1.4 μm) and short-wavelength (1.4–3.0 μm) infrared regions of the spectrum based on hybrid nanostructures consisting of PbS colloidal quantum dots and functional layers of ZnO and AgNW silver nanowires is proposed. Small-sized (12 × 12 μm) photosensitive elements with an energy barrier at the contact between layers of n- and p-type CQDs have been studied. The current-voltage characteristics, spectral dependences of optical absorption and relative spectral photosensitivity of Si(λ)/Si(λmax) barrier structures at room temperature have been studied. It is shown that the proposed architecture of barrier structures provides photosensitivity in a wide spectral range from 0.4 µm to 2.0 µm. An excess of the average value of the relative spectral sensitivity Si(λ)/Si(λmax) about 1.5 times compared to those previously observed in the wavelength range of 0.9–1.85 μm for barrier nanostructures from PbS CQDs was found.