White light-emitting diodes of GaN-based Sr2SiO4:Eu and the luminescent properties

Abstract

We have synthesized a Eu2+-activated Sr2SiO4 yellow phosphor and investigated an attempt to develop white light-emitting diodes (LEDs) by combining it with a GaN blue LED chip. Two distinct emission bands from the GaN-based LED and the Sr2SiO4:Eu phosphor are clearly observed at 400 nm and at around 550 nm, respectively. These two emission bands combine to give a spectrum that appears white to the naked eye. Our results showed that GaN (400-nm chip)-based Sr2SiO4:Eu exhibits a better luminous efficiency than that of the industrially available product InGaN (460-nm chip)-based YAG:Ce.

Highly oriented GaN films grown on ZnO buffer layer over quartz substrates by reactive sputtering of GaAs target

“…GaN has received enormous attention due to its applications in white light sources [4] and spintronic devices [5]. Piezoelectric properties of GaN and its negative electron affinity have also opened avenues of research, with promising applications [1,6,7].…”

Comparative investigation on synthesis and luminescence of Sr4Al14O25:Eu2+ applied in InGaN LEDs

“…Compared with the currently commercial white LED fabricated with a blue chip and a yellow phosphor YAG:Ce 3+ , the white LED fabricated with an NUV chip around 390-420 nm and corresponding phosphors has higher efficiency and color rendering index [2][3][4][5][6] because all the colors are determined by the phosphors. Therefore, the wavelength conversion phosphor materials play a crucial role in solid-state lighting innovation.…”

Combustion synthesis and luminescent properties of a blue-green emitting phosphor: (Ba1.95, Eu0.05)ZnSi2O7:B3+

“…Recently, remarkable progress has been made in the de- * E-mail: xuelh@mail.hust.edu.cn velopment of WLEDs using InGaN chips whose emission bands shift to near-UV [1][2][3][4]. Because UV-LED can offer a higher efficient solid-state light [5], more and more attention has been paid to the development of new phosphors that can be excited in the range of near-UV (370-420 nm) due to the necessity of increasing the efficiency of white light emitting solid-state devices [6].…”