Soft-lithographed up-converted distributed feedback visible lasers based on CdSe-CdZnS-ZnS quantum dots

Francesco Todescato Todescato, Ilaria Fortunati, Samuele Gardin, Eleonora Garbin, Elisabetta Collini, Renato Bozio, Jacek Jaroslaw Jasieniak, Gioia Della Giustina, Giovanna Brusatin, Stefano Toffanin, Raffaella Signorini

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Abstract

The development of a solution-deposited up-converted distributed feedback laser prototype is presented. It employs a sol-gel silica/germania soft-lithographed microcavity and CdSe-CdZnS-ZnS quantum dot/sol-gel zirconia composites as optical gain material. Characterization of the linear and nonlinear optical properties of quantum dots establishes their high absorption cross-sections in the one- and two- photon absorption regimes to be 1 x 10 -14 cm 2 and 5 x 10 4 GM, respectively. In addition, ultrafast transient absorption dynamics measurements of the graded seal quantum dots reveal that the Auger recombination lifetime is 220 ps, a value two times higher than that of the corresponding CdSe core. These factors enable the use of such quantum dots as optically pumped gain media, operating in the one- and two-photon absorption regime. The incorporation of CdSe-CdZnS-ZnS quantum dots within a zirconia host matrix affords a quantum-dot ink that can be directly deposited on our soft-lithographed distributed feedback grating to form an all-solution-processed microcavity laser. By exploiting sol-gel chemistry and the nanoimprinting process, a low-cost up-converted distributed feedback laser is realized. Properly synthesized graded CdSe-CdZnS-ZnS quantum dots are used as active gain material. The laser prototype efficiently works in the visible region, by pumping with one- or two-photon processes. This solution-processed device opens the way to the production of emission-tunable compact lasers.
Original languageEnglish
Pages (from-to)337 - 344
Number of pages8
JournalAdvanced Functional Materials
Volume22
Issue number2
DOIs
Publication statusPublished - 2012

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