Control of the threshold voltage in ZnO nanobelt field-effect transistors by using MoOx thin film. (19th May 2016)

• Record Type: Journal Article
• Authors: Qian, Haolei; Fang, Yanjun; Gu, Lin; Lu, Ren; Zhao, Ming; Wang, Wei; Wang, Yewu; Sha, Jian
• Is Part Of: Nanotechnology. Volume 27:Number 26(2016)
• Publication Date: 2016-05-19
• Subjects: ZnO nanobelts -- field effect transistors -- the threshold voltage; Nanotechnology -- Periodicals; Nanotechnology -- Periodicals; Nanotechnology; Publications périodiques; Nanotechnologies; Periodicals; 620.5
• DOI: 10.1088/0957-4484/27/26/265201
• Languages: English
• ISSNs: 0957-4484

Abstract

Abstract: We report on the feasible control of the threshold voltage ( V th ) in ultra-thin ZnO nanobelt FETs by using substoichiometric molybdenum trioxide (MoO x, x < 3) either as a modification layer on the surface of ZnO nanobelts or as electrodes instead of the widely used Ti/Au. ZnO nanobelt FETs using Ti/Au as the electrodes usually exhibit a negative threshold voltage, indicating n-channel depletion mode behavior, whereas ZnO FETs with MoO x /Au electrodes instead of Ti/Au show a positive shift of threshold voltage, exhibiting an n-channel type enhancement mode, which can be explained by a high Schottky barrier created at the interface of MoO x and the ZnO channel. In contrast, the decoration on the surface of ZnO channel by MoO x significantly increases the zero-bias conductivity and electron carrier concentration, and then negatively shifts the threshold voltage. We propose that MoO x thin film may play a passivation effect role, much more so than the doping effect role, due to the large amount of adsorbed species on as-grown ZnO nanobelts, especially oxygen species.