SIZE-DEPENDENT BAND-GAP AND DIELECTRIC CONSTANT OF SI NANOCRYSTALS

Based on the consideration on size-dependent temperature T-m(D) where D denotes the diameter of nanoparticles and nanowires or the thickness of thin films, the size-dependent band-gap Delta E-g(D) and dielectric constant epsilon(D) of low dimensional materials are modeled without any adjustable parameter. The model predicts an increase of the band-gap and a decrease of dielectric constant with drop of Si nanocrystals' size. The predicted results correspond to experimental and computer simulation results of Si nanocrystals.