IMAGE-CHARGE AND EXCITONIC EFFECTS ON THE OSCILLATOR STRENGTH OF SILICON QUANTUM DOTS

The enhancement of oscillator strength of silicon quantum dots (small crystallites) by the image charge and the excitonic electron-hole attr action is examined theoretically using a simple effective-mass model. While the distortion of the envelope function is found to be significa nt for the dot with a radius greater than 1 nm, the enhancement of the oscillator strength is significant only when the doe radius is smalle r than 1 nm.