Compositional dependency of Cd-S-Se quantum dots within silicate glass on color conversion for a white LED

Abstract

Quantum dot embedded glasses (QDEGs) were prepared by the conventional melt-quenching method to enhance its color conversion efficiency via optimizing the concentration of ZnS, ZnSe, and CdO within the silicate-based glass matrix. The QDEG, which contained 0.875 ZnS, 0.625 ZnSe, and 0.75 CdO (in mol%) and was heat treated at 500 degrees C for 10hours showed promising color conversion with an improved quantum yield of up to 25%. Color coordination of light-emitting diodes (LEDs) mounted with the QDEGs could be adjusted by tuning heat-treatment conditions and thickness control of QDEGs. The practical feasibility of the QDEG for a white LED is demonstrated with a reasonable glass thickness for LED packaging process. The formation of Cd-S-Se quantum dots within a glass matrix was identified by Raman and HR-TEM analyses. The effect of ZnSe and CdO on the formation of Cd-S-Se quantum dots within silicate glass is also discussed.