Nano-laser on silicon quantum dots

Abstract

A new conception of nano-laser is proposed in which depending on the size of nano-clusters (silicon quantum dots (QD)), the pumping level of laser can be tuned by the quantum confinement (QC) effect, and the population inversion can be formed between the valence band and the localized states in gap produced from the surface bonds of nano-clusters. Here we report the experimental demonstration of nano-laser on silicon quantum dots fabricated by nanosecond pulse laser. The peaks of stimulated emission are observed at 605nm and 693nm. Through the micro-cavity of nano-laser, a full width at half maximum of the peak at 693nm can reach to 0.5nm. The theoretical model and the experimental results indicate that it is a necessary condition for setting up nano-laser that the smaller size of QD (d<3nm) can make the localized states into band gap. The emission energy of nano-laser will be limited in the range of 1.7–2.3eV generally due to the position of the localized states in gap, which is in good agreement between the experiments and the theory.