Edge Electronic States and Direct Bandgap in Si Nanostructures on Silicon Oxide

The nanostructures on silicon oxide, as a new phase of matter, only allows conducting electrons to exist on its surfaces, in which the edge electronic states dramatically provide intriguing insights into the world of low-dimensional quantum systems featuring and proposing the mechanisms of optical mode formation. We report that the formations of a nanolayer and a nanodisk structure on silicon oxide have been produced by using a novel preparation methodology, mainly involving the pulsed laser deposition in oxygen environment and the coherent electron beam irradiation process. Here, the structures of the Si nanolayer and the nanodisk on silicon oxide have been observed in the TEM images. The electronic edge states in the Si nanostructures on silicon oxide for emission were demonstrated in photoluminescence measurement. The simulation model of the Si nanostructures on silicon oxide has been built according the experimental results. And the results of the simulating calculation demonstrated that the Dirac relation is competition with the quantum confinement effect in the geometry change of the Si nanostructures on silicon oxide, in which the transforming edge states into direct bandgap can be realized for better emission.