Piezotronic and Hall properties of individual ZnO microwire

Time 2018-11-08 11:00~11:25 Place Rm.600B
Code No. ME-O07 Session Chair
Name Prof. Sangwook Lee
Affiliation Ehwa Womans University
Title Piezotronic and Hall properties of individual ZnO microwire
Contents
We studied the electrical and electromechanical properties of individual ZnO microwire. ZnO microwires were produced by chemical vapor deposition method and characterized by X-ray diffraction and photoluminescence measurement. The mechanical properties of individual ZnO microwire were investigated by both of quasi-static method using AFM force-distance measurement and dynamic flexure method using laser interferometry[1]. To attach the nanoscale electrodes on the ZnO microwire, a suspended PMMA (Poly methyl methacrylate) ribbon structures were fabricated for making electrical connection between the micro wire and the bottom substrate. The estimated contact resistance by 4-probe measurement for ZnO microwire FETs fabricated by our method was found to be much lower than that of device fabricated by standard E-beam lithography and evaporation. We realized a suspended ZnO microwire based electromechanical device by using this fabrication method and investigated its piezoelectric properties. An efficient piezoelectric-induced current was detected when the individual suspended microwires were vibrating at their resonant frequency[2]. Using the PMMA ribbons, the Hall probes were also defined only on the top facet of the hexagonal surfaces. The 2-dimensinal charge carrier density and mobility of ZnO microwire were studied from the Hall measurements.[3]