Excitonic improvement of colloidal nanocrystals in salt powder matrix for quality lighting and color enrichment

Erdem T., SORAN ERDEM Z., Kelestemur Y., Gaponik N., Demir H. V.

OPTICS EXPRESS, vol.24, no.2, 2016 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 24 Issue: 2
  • Publication Date: 2016
  • Doi Number: 10.1364/oe.24.000a74
  • Journal Name: OPTICS EXPRESS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: No


Here we report excitonic improvement in color-converting colloidal nanocrystal powders enabled by co-integrating nonpolar green-and red-emitting nanocrystal energy transfer pairs into a single LiCl salt matrix. This leads to nonradiative energy transfer (NRET) between the cointegrated nanocrystals in the host matrix. Here we systematically studied the resulting NRET process by varying donor and acceptor concentrations in the powders. We observed that NRET is a strong function of both of the nanocrystal concentrations and that NRET efficiency increases with increasing acceptor concentration. Nevertheless, with increasing donor concentration in the powders, NRET efficiency was found to first increase ( up to a maximum level of 53.9%) but then to decrease. As a device demonstrator, we employed these NRET-improved nanocrystal powders as color-converters on blue light-emitting diodes ( LEDs), with the resulting hybrid LED exhibiting a luminous efficiency > 70 lm/Welect. The proposed excitonic nanocrystal powders potentially hold great promise for quality lighting and color enrichment applications. (C) 2015 Optical Society of America