Quantum dots have revolutionized the field of optoelectronics due to their atom-like electronic structure. However, the prospect of colloidal quantum-dot lasers has long been deemed impractical due to the high energies required to induce optical gain. But recent work published in Nature and led by Ted Sargent of the University of Toronto shows that the lasing threshold in cadmium selenide (CdSe)/cadmium sulphide (CdS) core-shell colloidal quantum dots can be lowered by squashing the CdSe core via a clever ligand exchange process……..
http://nanotechweb.org/cws/article/tech/68501