Abstract
The enhancement of nano-system properties, particularly low dimensional
structures, is of great importance for future devices. Using spin-polarized Density
Functional Theory (DFT), electronic and piezoelectric properties of II-VI monolayer
(ZnO, ZnS, CdO and CdS) are studied. Variations of these properties are further
studied under substitutional doping of non-metal atoms (boron and carbon). Doping
with a B/C atom transforms all the monolayers into half-metallic ferromagnet, with
changes arising mainly from p-orbitals of the dopant (B/C) atom. Reduction of band
gap energy from its pristine structure is observed in all the doped cases. Observations
predicted that the B-doped ZnO and ZnS monolayer showed negative structural
stiffness and negative piezoelectric tensors, while C-doping remains stable with
enhanced elastic as well as piezoelectric properties of the monolayer.