Javaux C, Mahler B, Dubertret B, Shabaev A, Rodina AV, Efros AL, Yakovlev DR, Liu F, Bayer M, Camps G, Biadala L, Buil S, Quelin X, Hermier JP. Thermal activation of non-radiative Auger recombination in charged colloidal nanocrystals.
Nat Nanotechnol 2013;
8:206-12. [PMID:
23396313 DOI:
10.1038/nnano.2012.260]
[Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Accepted: 12/17/2012] [Indexed: 05/19/2023]
Abstract
Applications of semiconductor nanocrystals such as biomarkers and light-emitting optoelectronic devices require that their fluorescence quantum yield be close to 100%. However, such quantum yields have not been obtained yet, in part, because non-radiative Auger recombination in charged nanocrystals could not be suppressed completely. Here, we synthesize colloidal core/thick-shell CdSe/CdS nanocrystals with 100% quantum yield and completely quenched Auger processes at low temperatures, although the nanocrystals are negatively photocharged. Single particle and ensemble spectroscopy in the temperature range 30-300 K shows that the non-radiative Auger recombination is thermally activated around 200 K. Experimental results are well described by a model suggesting a temperature-dependent delocalization of one of the trion electrons from the CdSe core and enhanced Auger recombination at the abrupt CdS outer surface. These results point to a route for the design of core/shell structures with 100% quantum yield at room temperature.
Collapse