Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7940921 | Superlattices and Microstructures | 2017 | 21 Pages |
Abstract
A multiscale computational study is performed to investigate how electronic structure, optical transitions, and terminal characteristics of nanostructured ZnO/MgO disk-in-wire emitters are governed by an intricate coupling of size-quantization, atomicity, and built-in structural and polarization fields. As for the models, an 8-band sp3 (with spin) atomistic tight-binding basis set was used to construct the Hamiltonian of the device in wurtzite crystal symmetry. Strain and the associated distortions of bond directions and bond lengths were modeled via the valence force-field (VFF) molecular mechanics framework. Specifically, in this work, a recently proposed ab initio based diameter-dependent model for the piezoelectric fields was implemented, which, as compared to the conventional diameter-independent model, was found to curb the influence of spontaneous (pyroelectric) polarization significantly. This particular finding is further illustrated through the calculation of electronic bandgap and localization of wavefunctions, optical emission characteristics, and the internal quantum efficiency of the device.
Keywords
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
Saad Mubarak Al-Qahtani, Abdulmuin Mostafa A. Abdullah, Md. Rezaul Karim Nishat, Shaikh S. Ahmed,