Wavelength dependent color conversion of CdSe/ZnS core/shell nanocrystals for white LEDs
Demir, Hilmi Volkan
2009 IEEE LEOS Annual Meeting Conference Proceedings
280 - 281
Item Usage Stats
Nanocrystals (NCs) provide narrow emission spectrum that can be conveniently tuned using quantum size effect. This ability to adjust and control emission spectrum of NCs makes them strong candidates for use in white color conversion light emitting diodes. For example, they are possibly be used for solid state lighting applications including indoor lighting, architectural lighting and scotopic street lighting, where spectrally tuned color conversion is necessary. In device research CdSe/ZnS core/shell nanocrystals are the most commonly used ones because of their good electronic isolation coming from ZnS shells and the resulting high quantum efficiency (QE) (i.e., >50% in solution) . However, when these nanocrystals are integrated into the solid film, e.g., for white light generation, their in-film QE undesirably drops (despite their high QE in solution). Hence, this adversely affects the overall efficiency of the integrating devices that incorporate these NCs . There have been various studies to understand the in-film optical properties of CdSe/ZnS core/shell NCs [3-5]. However, their spectrally resolved in-film quantum efficiency (i.e., the ratio of the number of photons emitted by the nanocrystal film to the number of photons absorbed in the nanocrystal film) and their photon conversion efficiency (i.e., the ratio of the number of photons emitted by the nanocrystal film to the number of photons incident to the nanocrystal film) have not been investigated in these previous studies. © 2009 IEEE.
High quantum efficiency
Photon conversion efficiencies
Quantum size effects
Solid-state lighting application
Light emitting diodes
Semiconductor quantum dots
Published Version (Please cite this version)http://dx.doi.org/10.1109/LEOS.2009.5343274
Showing items related by title, author, creator and subject.
A photometric investigation of ultra-efficient LEDs with high color rendering index and high luminous efficacy employing nanocrystal quantum dot luminophores Erdem, T.; Nizamoglu, S.; Sun, X. W.; Demir, Hilmi Volkan (Optical Society of America, 2009-12-24)We report a photometric study of ultra-efficient light emitting diodes (LEDs) that exhibit superior color rendering index (CRI) and luminous efficacy of optical radiation (LER) using semiconductor quantum dot nanocrystal ...
Erdem, Talha (Bilkent University, 2011)Today almost one-fifth of the world‟s electrical energy is consumed for artificial lighting. To revolutionize general lighting to reduce its energy consumption, high-efficiency, high-quality light-emitting diodes (LEDs) ...
Erdem, T.; Soran-Erdem Z.; Sharma, V. K.; Keleştemur, Y.; Adam, M.; Gaponik N.; Demir, Hilmi Volkan (Royal Society of Chemistry, 2015)In this work, we propose and develop the inorganic salt encapsulation of semiconductor nanocrystal (NC) dispersion in a nonpolar phase to make a highly stable and highly efficient colour converting powder for colour ...