State-resolved observation in real time of the structural dynamics of multiexcitons in semiconductor nanocrystals

Autor:	Eva A. Dias, Samuel L. Sewall, Patanjali Kambhampati, Ryan R. Cooney, Pooja Tyagi
Rok vydání:	2011
Předmět:	Materials science Auger effect Binding energy Dynamics (mechanics) Condensed Matter Physics Molecular physics Electronic Optical and Magnetic Materials symbols.namesake Nanocrystal Quantum dot symbols Semiconductor nanocrystals Stimulated emission Biexciton
Zdroj:	Physical Review B. 84
ISSN:	1550-235X 1098-0121
DOI:	10.1103/physrevb.84.235304
Popis:	Biexciton processes in semiconductor nanocrystals, e.g. optical gain, are widely treated as arising from structureless biexcitons. We challenge this view by observing the binding energies of hot biexcitons in CdSe nanocrystals. These experiments reveal a previously unobserved spectrum in the biexciton binding energies that correlates with hole configuration. Analysis of this spectrum of binding energies shows that the onset and the decay of optical gain in nanocrystals are dictated by cooling dynamics of the hot biexciton rather than Auger recombination. In addition to the structural dynamics of the biexciton, we show that the capacity to control optical gain bandwidth in these nanocrystals arises from stimulated emission from higher multiexcitons.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::934e3bbf3dc126a19f7eaffdb97b31f7 https://doi.org/10.1103/physrevb.84.235304 Zobrazit plný text záznamu