The elastic, piezoelectric, electronic, and optical properties of a single ZnO monolayer (SZOML) with graphene-like structure are investigated from the first-principles calculations. The phonon dispersion curves contain three acoustic and three optical branches. At Γ point, the out-of-plane acoustic mode has an asymptotic behavior ω(q)=Bq2 with B=1.385×10−7 m2/s, while two in-plane acoustic modes have sound velocities 2.801 km/s and 8.095 km/s; the other three optical modes have frequencies 250 cm−1, 566 cm−1, and 631 cm−1. The elastic and piezoelectric constants are obtained from the relaxed ion model. It is found that the SZOML is much softer than graphene, while it is a piezoelectric material. The electronic band gap is 3.576 eV, which implies that the SZOML is a wide band gap semiconductor. Many peaks exist in the linear optical spectra, where the first peak at 3.58 eV corresponds to the band gap of SZOML.
@article{arxiv.0901.1112,
title = {First-principles study on physical properties of a single ZnO monolayer with graphene-like structure},
author = {Z. C. Tu},
journal= {arXiv preprint arXiv:0901.1112},
year = {2010}
}