한국재료학회지 제28권 제11호 (p.671-679)

산화아연 나노와이어의 압전거동에 대한 분석

Finite Element Analysis of the Piezoelectric Behavior of ZnO Nanowires
키워드 :
zinc oxide,ZnO,nanostructure,piezoelectricity,energy harvesting

목차

Abstract
1. 서 론
2. 유한요소 해석
  2.1 해석모델
  2.2 산화아연의 기계적, 전기적 물성
  2.3 하중조건
3. 결과 및 고찰
  3.1 단순 압축
  3.2 순 굽힘
  3.3 좌굴
  3.4 나노와이어 압전소자의 구성을 위한 제언
4. 결 론
References

초록

Finite element analyses are carried out to understand the piezoelectric behaviors of ZnO nanowires. Three different types of ZnO nanowires, with aspect ratios of 1:2. 1:31, and 1:57, are analyzed for uniaxial compression, pure bending, and buckling. Under the uniaxial compression with a strain of 1.0 × 10−4 as the reference state, it is predicted that all three types of nanowires develop the same magnitude of the piezoelectric fields, which suggests that longer nanowires exhibit higher piezoelectric potential. However, this prediction is not in agreement with the experimental results previously reported in the literature. Such discrepancy is understood when the piezoelectric behaviors under bending and buckling are considered. When only the strain field due to bending is present in bending or buckling, the antisymmetric nature of the through-thickness stain distribution indicates that two piezoelectric fields, the same in magnitude and opposite in sign, develop along the thickness direction, which cancels each other out, resulting in a zero net piezoelectric field. Once additional strain contribution due to axial deformation is superposed on the bending, such field cancelling is compensated for due to the axial component of the piezoelectric field. Such numerical predictions seem to explain the reported experimental results while providing a guideline for the design of nanowire-based piezoelectric devices.