Investigation of piezoelectric properties of MgxZn1-xO/ZnO heterostructure thin films

Abstract

We investigate the piezoelectric coefficient (d33) of MgxZn1-xO and MgxZn1-xO/ZnO films with the variation of the Mg concentration The films are grown on Si (111) substrate using MgO and ZnO as targets by radio frequency magnetron sputtering The thickness of all the films is fixed at around 500 nm for both MgxZn1-xO and MgxZn1-xO/ZnO films All the films have high crystallinity with preferred orientation along c-axis and that shows columnar microstructures by X-ray diffractometry Scanning electron microscopy and Transmission electron microscopy Besides the substitution of magnesium ions at zinc sites is confirmed by X-ray diffraction patterns and UV-Visible spectroscopy The d33 values reach 41 7 pm/V and 47 5 pm/V for MgxZn1-xO and MgxZn1-xO/ZnO (x = 0 30) films which is around 3 4 and 3 8 times larger than pure ZnO films (12 4 pm/V) by piezoelectric force microscopy The films may be considered as promising candidate for piezoelectric nanogenerators and piezotronic transistors

Date of Award	2019
Original language	English
Supervisor	Jow-Lay Huang (Supervisor)