Blue semiconductor nanocrystal laser

We demonstrate tunable room-temperature amplified spontaneous emission and lasing from blue-emitting core-shell CdS/ZnS nanocrystals (NCs) stabilized in a sol-gel derived silica matrix. Variable stripe length measurements show that these NC-silica composites have a modal gain of similar to100 cm(-1) at room temperature. Coating microspheres with a NC-silica composite film via a facile process resulted in uniform resonators that exhibit room-temperature lasing over long periods of continuous excitation. This work opens up a spectral window for emission tunable, microscale NC-based lasers. (C) 2005 American Institute of Physics.