关键词: Au/单根SnO2纳米线/Au两端纳米器件/
电输运/
氧空位/
第一性原理计算
English Abstract
Electrical transport properties and related mechanism of single SnO2 nanowire device
Chen Ya-Qi1,2,Xu Hua-Kai2,
Tang Dong-Sheng2,
Yu Fang2,
Lei Le2,
Ouyang Gang2
1. School of Electronic Information and Electrical Engineering, Xiangnan University, Chenzhou 423000, China;
2. Key Laboratory of Low Dimensional Quantum Structures and Quantum Control, School of Physics and Electronics, Hunan Normal University, Changsha 410006, China
Fund Project:Project supported by the National Natural Science Foundation of China (Grant No. 11574080), the scientific research project of Xiangnan University (Grant No. 2016XJ31).Received Date:07 August 2018
Accepted Date:08 October 2018
Published Online:20 December 2019
Abstract:Defect engineering in a semiconductor nanowire-based device has aroused intensive attention due to its fascinating properties and the potential applications in nanoelectronics. Here in this work, in order to investigate the effect of oxygen defects on the electrical transport properties in a SnO2-nanowire-based device under normal environment, we synthesize an individual SnO2 nanowire, by a thermal chemical vapor deposition method and further construct a two-terminal Au/SnO2 nanowire/Au device by using optical lithography. The electrical transport properties of a single SnO2 nanowire device are measured under the condition of air and vacuum after hydrogen reduction. It is found that the transport performances in air are unusually different from those in vacuum. Strikingly, the reduction of electric current through the device and the increment of contact barrier of the Au/SnO2 interface in air can be observed with the I-V scan times increasing. While in vacuum, the current increases and a change from Schottky contact to ohmic contact at the interface between Au and SnO2 can be obtained by performing more scans. Our results demonstrate that the oxygen vacancy concentrations caused by the oxygen atom adsorption and desorption on the surface of nanowires play the key role in the transport properties. Furthermore, we calculate the relevant electronic properties, including energy band structure, density of states, as well as I-V characters and transmission spectrum at the interface of Au/SnO2 within the framework of density functional theory. We find that the bandgap of SnO2 nanowires decreases with oxygen vacancy concentration increasing. Also, the existence of oxygen defects enlarges the electron transmission at the interface of Au/SnO2 and enhances electrical transport. Therefore, our results provide a new strategy for designing the integrated nano-functional SnO2-based devices.
Keywords: two-terminal Au/SnO2 nanowire/Au device/
electrical transport/
oxygen vacancy/
first-principles calculations
