Dielectric suppression and its effect on photoabsorption of nanometric semiconductors

Deeper insight is presented into the origin of the dielectric suppression and its effect on the photoabsorption of nanometric semiconductors. Consistency between modelling predictions and experimental observations reveals that the dielectric suppression originates from the enhancement of the crystal field due to surface bond contraction and the rise of the surface-to-volume ratio with decreasing particle size. The suppression of the dielectric function will lead to a blue shift in photoabsorption edges, which may find application in microelectronic and photonic devices of nanometre scales.