Tuning dielectric constant and Young's modulus by nanofabrication

Understanding the origin, the trend and the scale of the relative change of the mechanical strength and the dielectric properties of a nanometric solid is of great importance in designing solid-state device. Here we present a model that describes the nature and behavior of a nanosolid including spherical dots, wires and ultrathin films. Consistency between predictions and experimental observations confirms that the size-driven property-change originates from the chemical bond contraction at surface and the rise in the surface-to-volume ratio of the nanosolid. It is found that the bond contracts by as high as 14 percent and the corresponding Young's modulus increase by 100 percent at surface, and that the dielectric constant of semiconductors decreases with reducing the dimension of the solid, which leads to the blue shift in the photoluminescence and absorption edges.