resumo
Currently, it is understood that the carrier recombination rate in semiconductors can be modified by metals due to pure electrodynamic interactions through surface plasmons. We propose here an electrostatic mechanism for carrier-metallic nanoparticle interaction comparable in effect to plasmonic interactions. Arising from Coulomb attraction of electrons and holes to their images in metal, this mechanism produces large carrier concentrations near metallic nanoparticles. Increased concentration results in increased quantum efficiency and enhances the rate of e-h recombination. This manifests as emission enhancement in InGaN quantum wells radiating in the near-UV region. The proposed fundamental mechanism provides a new perspective for improving the efficiency of broadband light emitters.
palavras-chave
EMISSION; SURFACE; PHOTOLUMINESCENCE; NANOCAVITIES; PLASMONICS
categoria
Physics
autores
Llopis, A; Lin, J; Pereira, SMS; Trinidade, T; Martins, MA; Watson, IM; Krokhin, AA; Neogi, A
nossos autores
Manuel António Martins da Silva
Investigador
Sérgio Manuel de Sousa Pereira
Investigador principal
Tito Trindade
Professor Catedráticoagradecimentos
The authors would like to acknowledge the support of the Center for Commercialization of Fluorescence Technologies (CCFT) at the University of North Texas Health Science in Fort Worth, Texas. The authors acknowledge the assistance of Ryan Rich and Zygmunt Gryczynski for the microphotoluminescence measurements. This work is supported by the US Department of Energy Grant No. DE-FG02-06ER46312, National Science Foundation (NSF) Grant No. DMR-0520550, NSF IRES program No. 623642, and by Fundacao para a Ciencia e Tecnologia (FTC/FEDER) Project PTDC/CTM/101453/2008.