Enhancement of piezoelectric properties of ZnO thin films by Yttrium doping for piezoelectric nanogenerators

Abstract

Wurtzite structure materials such as ZnO are considered to be the promising candidate for nanogenerators because of its unique properties In this paper we investigate the effect of yttrium(Y) doping on the piezoelectric coefficient of ZnO thin films synthesized on p-type Si (111) substrates via RF magnetron sputtering XRD diffraction patterns show that all films presented ZnO wurtzite structure with c-axis preferential orientation and high crystallinity under small amount of yttrium doping The chemical binding energy and composition of the thin films are measured by XPS and the results confirm the substitution of zinc by yttrium The electric hysteresis loop exhibits the ferroelectric property of Y doped ZnO thin films which is the key to the enhancement of piezoelectric properties The measurement of piezoelectric coefficient (d33) by PFM showing that Y doped ZnO thin films reach 49 6 pm/V at yttrium concentration is 1 6 a t % which is higher than d33 of pure ZnO thin films The Y doped ZnO based-nanogenetors present better output performance than that of ZnO based-nanogenerators so it is considered that Y doped ZnO thin films have more potential to be developed on the field of nanogenerators

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