標題: Nanocontact disorder in InP nanowire devices for the enhancement of visible light and oxygen gas sensitivities
作者: Lin, Yen-Fu
Chang, Chia-Hung
Hung, Tsu-Chang
Liu, Zhaoping
Fang, Jiye
Jian, Wen-Bin
電子物理學系
Department of Electrophysics
關鍵字: nanowire electronics;nanocontact;InP nanowire;disorder
公開日期: 1-Jan-2017
摘要: InP nanowires, synthesized through a self-seeded growth approach, are used in the fabrication of field-effect transistors which consist of source, drain, and back-gate electrodes. The weak gating voltage dependence implies low carrier concentrations whereas its behavior reveals native n-type doping in InP nanowires. These InP nanowire devices exhibit a vast variation of room-temperature resistance that raises a question about contact resistance. For devices of low room-temperature resistance, electron transport in InP nanowires is investigated using temperature dependent resistance in the temperature range between 80 and 300 K, and it can be analyzed using the model of thermal activation. For other devices of high room-temperature resistance, we take into account nanocontact resistance. Models of both Schottky contact and Mott's variable range hopping (VRH) are considered. The two resistances are connected in parallel to give total contact resistance of InP nanowire devices. After fitting experimental data by the proposed model, we estimate effective Schottky barriers and disorder contributions to nanocontact resistance. The effective Schottky barrier, and the nanocontact Schottky and Mott's VRH resistances are plotted as a function of the device room-temperature resistance which indicates the scale of disorder. Using room-temperature resistance of InP nanowire devices, the devices are classified into nanowire-or contact-dominated devices. The two different class of devices are used to check their photo-and gas-sensitivities. The contact-dominated InP nanowire devices show low dark current and low photocurrent as usual, but these contact-dominated devices give high ratio of photo-to dark-current. That result reveals a high photo-sensitivity for those devices of high nanocontact resistance. On the other hand, for gas sensing experiments, the contact-dominated devices show as well a high ratio of resistance under O-2 to that under N-2 gas exposure. (C) 2017 The Authors. Published by Elsevier B.V.
URI: http://dx.doi.org/10.1016/j.piutam.2017.03.034
http://hdl.handle.net/11536/146848
ISSN: 2210-9838
DOI: 10.1016/j.piutam.2017.03.034
期刊: 2016 IUTAM SYMPOSIUM ON NANOSCALE PHYSICAL MECHANICS
Volume: 21
起始頁: 33
結束頁: 39
Appears in Collections:Conferences Paper


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