Macrocrystals of semiconductor nanocrystals for light emitting diodes
Author
Akcalı, Halil
Advisor
Demir, Hilmi Volkan
Date
2013Publisher
Bilkent University
Language
English
Type
ThesisItem Usage Stats
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Abstract
Worldwide energy consumption is rapidly increasing and general lighting
constitutes an important portion of it. By considering most of the lighting
sources to rely on fluorescent lamps today, solid-state lighting has a great
potential especially with recent advances on efficiency and color quality of
white light-emitting diodes (LEDs). One of the most promising approaches for
the current white LED technology is based on the use of color-conversion
materials. In recent years semiconductor nanocrystal quantum dots (NQDs) have
arisen as an important class of color-convertors because of their tunable and
superior optical properties and today there are various prototypes and
commercial products. Recently, a new material system involving macrocrystals
of NQDs has been introduced. In this thesis, different types of NQD
macrocrystals are developed and studied for the white LED application. These
macrocrystals of NQDs are produced by forming ionic salts in the presence of
water soluble NQDs. This enhances the stability of NQDs wrapped in salt solids
and allows for high integration capability in powder form to current LED
technology employing commercial encapsulants. This thesis also includes a
colorimetric study of white LEDs using such macrocrystals of NQDs to
demonstrate high-quality white light with high color rendering index, low
correlated color temperature, and high luminous efficacy of optical radiation.
Keywords
Quantum dot incorporated macrocrystalssemiconductor nanocrystals
white light-emitting diodes
color science