Hybrid Structure of PbS QDs and Vertically-few-layer MoS2Nanosheets Array for Broadband Photodetector.

A novel three-dimensional (3D) vertically-few-layer MoS2(V-MoS2) nanosheets- zero-dimensional (0D) PbS quantum dots (QDs) hybrid structure based broadband photodetector was fabricated, and its photoelectric performance was investigated in detail. We synthesized the V-MoS2nanosheets by chemical vapor deposition (CVD), using the TiO2layer as the induced layer, and proposed a possible growth mechanism. The use of the TiO2induction layer successfully changed the growth direction of MoS2from parallel to vertical. The prepared V-MoS2nanosheets have a large specific surface area, abundantly exposed edges and excellent light absorption capacity. The V-MoS2nanosheets detector was then fabricated and investigated, which exhibits a high sensitivity for 635 nm light, a fast response time and an excellent photoelectric response. The V-MoS2 nanosheets with a height of approximately 1 μm successfully broke the light absorption limit caused by the atomic thickness. Finally, we fabricated the PbS QDs/V-MoS2nanosheets hybrid detector and demonstrated their potential for high-performance broadband photodetectors. The response wavelength of the hybrid detector extends from the visible band to the near-infrared band. The responsivity of the hybrid detector reaches 1.46 A/W under 1450 nm illumination. The combination of 3D MoS2nanosheets and QDs further improves the performance of MoS2-based photodetector devices. We believe that the proposed zero-dimensional QDs and three-dimensional vertical nanosheets hybrid structure broadband photodetector provides a promising way for the next-generation optoelectronic devices.