High color rendering white light-emitting diodes based on a green silicate phosphor mixed with a red dye-bridged hybrid

Abstract

White light-emitting diodes (LEDs) using a wavelength converter composed of a red dye-bridged hybrid (DBH) mixed with a green silicate phosphor are fabricated. The red DBH is synthesized by chemically bonding epoxy functional oligosiloxane and red fluorescent dye for application in a red wavelength converter of white LEDs. To date, inorganic phosphors and quantum dots have been reported as red emitters. In this report, we suggest a dye based red wavelength converter for high color rendering white LEDs. The structural and optical properties of the DBH are evaluated. The fabricated white LEDs have a high color rendering index up to 90. They show facile color temperature tunability, a broad color gamut, and sufficient efficacy of 33.3 lm W⁻¹ for applications in lighting technology. Also, both forward-bias current stability and long-term thermal stability are achieved for solid-state lighting applications.