Phys.org November 29, 2019
Colloidal quantum dots (CQDs) are highly promising materials for light amplification. But band-edge state degeneracy demands multiple excitons to achieve population inversion increasing the lasing threshold and limits the gain lifetime. Researchers in Singapore have demonstrated that the amplified spontaneous emission (ASE) threshold is controllable in a device where CQD film is exposed to an external electric field. Specifically, singly charged CQDs lower the threshold due to the preexisting electron in the conduction band, while strongly enhanced Auger recombination in doubly charged CQDs stymies the ASE. According to the researchers the next big challenge in laser research is to develop nanoscale lasers and integrate them into on-chip photonic devices and ultrasensitive sensors. This would have significant impact on data and information processing…read more. Open Access TECHNICAL ARTICLE
Glass plates with applied colloidal quantum dots which can emit different spectrums light when electrically and optically pumped, which makes it suitable as a laser material. Credit: Nanyang Technological University