Modeling Size and Shape Dependence of Electro-Optical Properties of Semiconductor Nanosolids

Based on cohesive energy, the size and shape effect on Bandgap, Dielectric constant and Phonon frequency of low-dimension semiconductor nanomaterials are predicted with structural miniaturization down to the nanoscale. It is projected that nanomaterial's optical and electrical properties no longer remain constant but become tunable. The model reports that the bandgap increases while the dielectric constant and phonon frequency drop on decreasing size to the nanoscale. The bandgap variation, dielectric constant and phonon frequency are reported for spherical, thin film, nanowire, regular tetrahedral and regular octahedral shapes of semiconductor nanosolids. The shape effect becomes prominent as the form changes from spherical to regular tetrahedral shape up to the size limit of 20 nm. A good agreement between our model predictions and the available experimental and simulation data justifies the theory's validity.