Advanced Nanofabrication Technologies for Making Photo-Response Devices Based on Emerging Layered Transition Metal Dichalcogenides.

[摘要] Emerging layered semiconductor materials, such as layered transition metal dichalcogenides (TMDCs), have exhibited attractive optoelectronic properties and hold a significant potential to be implemented for making new photoresponse devices. However, to realize working TMDC-based photoresponse devices for practical photovoltaic and photodetection applications, we need to (i) create new nanofabrication and nanomanufacturing technologies capable of producing TMDC devices with deterministic properties, architectures, and arrangements, (ii) develop new materials processing approaches capable of modulating various TMDCs to enable different device applications, and (iii) advance the device physics for understanding and leveraging the unique photonic properties of layered semiconductors. The research works presented in this thesis sought to advance the scientific/technical knowledge toward addressing the needs mentioned above and specifically focused on three relevant topics: (1) invention and demonstration of plasma-assisted transfer nanoprinting technology capable of producing orderly arranged layered material structures into device sites; (2) development and study of plasma-assisted doping processes, which can result in permanently stable doping effects in layered semiconductors; (3) characterization of a series of photoresponse devices based on emerging layered transition metal dichalcogenides (TMDCs), which were fabricated using various techniques, including plasma-assisted doping, stacking of graphene-TMDC heterostructures, and thin-film-metal-induced surface charge transfer (SCT) doping. The presented works have advanced the scientific knowledge and technical capability toward realizing working TMDC-based photoresponse devices for practical photovoltaic and photodetection applications. Additionally, the nanofabrication approaches developed in these works can be generally used for making other TMDC-based nanoelectronic and photonic devices, and the obtained device physics knowledge is anticipated to greatly leverage the uniquely advantageous optoelectronic properties of semiconducting TMDCs for enabling new device applications.

[发布机构] University of Michigan

[效力级别] two dimensional materials

[关键词] Photovoltaics;two dimensional materials;transition metal dichalcogenides;heterostructure;nanotechnology;Mechanical Engineering;Engineering;Mechanical Engineering