Multiexcitonic two-state lasing in a CdSe nanocrystal laser

We report simultaneous amplified spontaneous emission from two different multiexcitonic transitions -1S(e)-1S(3/2) and 1P(e)-1P(3/2)(-) of colloidal CdSe nanocrystals (NCs) stabilized in high volume fraction in titania matrices. Two-state lasing from both multiexcitonic transitions is achieved in a surface-emitting distributed feedback CdSe NC laser. Variable stripe length measurements show that the gain from the 1P(e)-1P(3/2) transition is approximately twice that of the -1S(e)-1S(3/2) transition for 4.2 nm radius CdSe/ZnS core-shell NCs. (C) American Institute of Physics.