Modeling Dielectric Constant of Semiconductor Nanocrystals

A simple and unified model has been established for size- and composition-dependent dielectric constant ε(x,D) based on a size-dependent melting-temperature model, where x is the fraction of composition, D denotes the diameter of nanoparticles and nanowires, and the thickness of thin films. It demonstrates that depending on the dimension of nanocrystals, ε(x,D) decreases with different trend as D drops, while ε(x,D) is a nonlinear function of x. The theoretical prediction agrees approximately with experimental and computer simulation results of semiconductor nanocrystals in single phase or multiphases.