Piezoelectricity in two-dimensional materials: Comparative study between lattice dynamics and ab initio calculations
PHYSICAL REVIEW B, vol.95, no.12, 2017 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 95 Issue: 12
- Publication Date: 2017
- Doi Number: 10.1103/physrevb.95.125415
- Journal Name: PHYSICAL REVIEW B
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
- Open Archive Collection: AVESIS Open Access Collection
- Anadolu University Affiliated: Yes
Abstract
The elastic constant C-11 and piezoelectric stress constant e(1),(11) of two-dimensional (2D) dielectric materials comprising h-BN, 2H-MoS2, and other transition-metal dichalcogenides and dioxides are calculated using lattice dynamical theory. The results are compared with corresponding quantities obtained with ab initio calculations. We identify the difference between clamped-ion and relaxed-ion contributions with the dependence on inner strains which are due to the relative displacements of the ions in the unit cell. Lattice dynamics allows us to express the inner-strain contributions in terms of microscopic quantities such as effective ionic charges and optoacoustical couplings, which allows us to clarify differences in the piezoelectric behavior between h-BN and MoS2. Trends in the different microscopic quantities as functions of atomic composition are discussed.