E U Rafailov
Aston University, UK
Title: New generation of a single-chip LEDs with superior colour rendering emission
Biography
Biography: E U Rafailov
Abstract
Development of LED-based solid state lighting has led to understanding that various lighting applications provide very different requirements to the quality and characteristics of white light. The mainstream applications, like outdoor (street) and indoor lightings are primarily aimed at saving electricity consumption and, therefore, need maximum efficacy and minimum cost of white-light source. Warm-white emission with superior CRI is demonstrated using a di-chromatic monolithic InGaN multiple quantum well LED and two phosphors. The LED emitting simultaneously blue (440 nm) and cyan (480 nm) photons pumps the vertically stacked red (~ 620 nm) and green (~540 nm) phosphor. An excellent average colour rendering index, CRI (Ra) of 98.4 with CCT of 3400 K is achieved. With appropriate heat sink assembly and industry standard packaging to improve extraction efficiency we estimate these devices can achieve Luminous Efficacy and Wall-plug Efficiency (WPE) of more than 160 lm/W and 55% respectively.