3C-SiC-induced peak emission intensity in photoluminescence spectrum of SiC/SiO2 core–shell nanowires using first-principles calculations

Abstract

In light of the recent publication of a report on the preparation of crystalline silicon carbide nanowires (NWs) covered with silicon oxide (SiC/SiO2) core–shell nanowires at low temperature, this study uses first-principles calculations based on the related transmission electron microscope micrographs to study hydrogen-passivated 3C-, 2H-, 4H-, and 6H-SiC NWs and their combinations. The aim is to examine charge transfers at the 2H/3C and the 2H/4H/3C interfaces in case there is no limit to periodicity. The orbital wavefunctions in the calculated interfaces exhibited changes from valence band maximum to conduction band minimum. The results of the photoluminescence spectrum showed a peak at a wavelength of 392 nm in terms of the intensity of emission, where this has been expected for such microstructures. Zhang et al. claimed that the source of this peak lies in nanoscale 6H-SiC layers, but our simulations based on experimental measurements indicate that it likely originates in 3C-SiC nanowires with a diameter of 1.5 nm.