title: Red, Yellow, Green, and Blue Amplified Spontaneous Emission and Lasing Using Colloidal CdSe Nanoplatelets.
abstract: There have been multiple demonstrations of amplified spontaneous emission (ASE) and lasing using colloidal semiconductor nanocrystals. However, it has been proven difficult to achieve low thresholds suitable for practical use of nanocrystals as gain media. Low-threshold blue ASE and lasing from nanocrystals is an even more challenging task. Here, we show that colloidal nanoplatelets (NPLs) with electronic structure of quantum wells can produce ASE in the red, yellow, green, and blue regions of the visible spectrum with low thresholds and high gains. In particular, for blue-emitting NPLs, the ASE threshold is 50 μJ/cm(2), lower than any reported value for nanocrystals. We then demonstrate red, yellow, green, and blue lasing using NPLs with different thicknesses. We find that the lateral size of NPLs does not show any strong effect on the Auger recombination rates and, correspondingly, on the ASE threshold or gain saturation. This observation highlights the qualitative difference of multiexciton dynamics in CdSe NPLs and other quantum-confined CdSe materials, such as quantum dots and rods. Our measurements of the gain bandwidth and gain lifetime further support the prospects of colloidal NPLs as solution-processed optical gain materials.
authors: Department of Chemistry and the James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
authors: Chunxing
authors: C
authors: She
authors: Department of Chemistry and the James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
authors: Igor
authors: I
authors: Fedin
authors: Department of Chemistry and the James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.
authors: Dmitriy S
authors: DS
authors: Dolzhnikov
authors: Graduate Program in the Biophysical Sciences, the James Franck Institute, and The Institute for Biophysical Dynamics, University of Chicago , Chicago, Illinois 60637, United States.
authors: Peter D
authors: PD
authors: Dahlberg
authors: Department of Chemistry and the James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.|The Institute for Biophysical Dynamics, University of Chicago , Chicago, Illinois 60637, United States.
authors: Gregory S
authors: GS
authors: Engel
authors: Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.|Department of Chemistry, Northwestern University , Evanston, Illinois 60208, United States.
authors: Richard D
authors: RD
authors: Schaller
authors: Department of Chemistry and the James Franck Institute, University of Chicago , Chicago, Illinois 60637, United States.|Center for Nanoscale Materials, Argonne National Laboratory , Argonne, Illinois 60439, United States.
authors: Dmitri V
authors: DV
authors: Talapin
mesh_terms: D019187:Cadmium Compounds / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D049408:Luminescent Agents / Q000737:chemistry; D008163:Luminescent Measurements; D045663:Quantum Dots / Q000737:chemistry* / Q000648:ultrastructure; D018036:Selenium Compounds / Q000737:chemistry*
chemical_list: D019187:Cadmium Compounds; D003102:Colloids; D049408:Luminescent Agents; D018036:Selenium Compounds; C058667:cadmium selenide
keywords: Auger recombination; amplified spontaneous emission; lasing; nanoplatelets; optical gain; semiconductor nanocrystals