study of transition metal metal oxide and metal dichalcogenide nanohybrids for photodetection application

Abstract

The fabrication of broadband photodetectors by using photoactive nanomaterials like ZnO-WS2, ZnO-MoS2, Ag-WS2, and Ni-WS2 heterostructures have been fabricated. Additionally, different substrates such as silicon (Si), Indium Tin Oxide (ITO), and flexible cellulose paper have been used for the fabrication of large-area devices. It was expected that all the nanomaterials would cover the spectral range from UV to visible light. We focused on the plasmonic metal nanoparticles like silver (Ag) and nickel (Ni) decorated on WS2 nanosheets for enhanced photoresponsivity. Investigation of structural, compositional, morphological, and optical analysis was accomplished to optimize the properties of the heterostructures. By combining the photosensitive TMs/TMOs with semiconducting TMDCs, efficient photo-carrier extraction can be achieved over a broad spectral region. For quantitative analysis, response speed, external quantum efficiency, specific detectivity, flexibility, stability, etc. have been calculated. The thesis has been divided into six chapters. newlineChapter 1, comprises a literature survey on different properties of 2D materials like transition metal dichalcogenides (TMDCs), graphene, etc. has been included. newlineChapter 2, discusses the p-Si/n-ZnO-WS2 and p-Si/n-ZnO-MoS2 heterojunction photodiode have been discussed. newlineChapter 3, discusses the p-Si/n-Ag-WS2 and p-Si/n-Ni-WS2 heterojunction photodiode have been discussed. newlineix newlineChapter 4, discusses the flexible, large area, broadband, and highly stable photodetectors based on Graphite/ZnO-WS2 nanohybrid on paper. newlineChapter 5, discusses the ITO/ZnO-WS2 heterostructure/ITO based photodetector. newlineChapter 6, the summary of the work and its future scope are discussed. newline