The effect of rare earth on color conversion properties of Cd-S-Se quantum dot embedded silicate glasses for white LED

Abstract

Various rare earth (RE) oxides such as Pr2O3, Dy2O3, Ho2O3, and Er2O3 were introduced into Cd-S-Se quantum dot embedded glasses (QDEGs) to investigate their effect on the color conversion properties of the Cd-S-Se QDEGs. The absorption and emission peak wavelengths due to the excitonic transition of the Cd-S-Se QDs were modified by the introduction of RE oxides, implying their influence on QD formation. The photoluminescence of the various QDEGs RE oxides under 450 nm excitation were monitored and compared with the un-doped QDEGs. White LEDs (wLEDs) were also fabricated with the RE-doped QDEGs and their color conversion properties, such as quantum yield (QY), luminous efficacy, correlated color temperature (CCT) and color rendering index (CRI) were examined. Transmission electron microscope (TEM) revealed that the size and spatial distribution of the QDs were improved by the RE-oxides. Their effect on QD formation within the silicate glass was discussed using Raman spectroscopy.