Yellow phosphors of high quantum yields excitable by both ultraviolet and blue light with Gd3BWO9 as the host

Abstract

Yellow phosphors play an important role in the fabrication of white light LEDs. In this study, we synthesized a series of yellow phosphors with Gd3BWO9 (GBWO) as the host material. The broad emission band in the range of 400 ​nm–620 ​nm is attributed to the 3P0→1S0 transition of Bi3+. The emission color is tuned from green to yellow by co-doping of Eu3+ or Sm3+ with Bi3+ in GBWO. Additionally, yellow phosphors excited by blue light (λex ​= ​487 ​nm) were obtained by co-doping Tb3+ with Eu3+ or Sm3+ in GBWO host. The emission can be tuned from green to yellow and orange by adjusting the ratio of Tb3+/Eu3+ and Tb3+/Sm3+. The quantum yield of GBWO:0.25 ​Tb3+, 0.03Eu3+ yellow phosphor reaches 70.2%, and the quantum yield of GBWO:0.25 ​Tb3+, 0.05Eu3+ orange phosphor is as high as 83.7%. The present yellow phosphors that can be excited by both ultraviolet and blue light and having high quantum yields can be candidates for the application in white LED.