Brownish red emitting YAG:Ce3+,Cu+ phosphors for enhancing the color rendering index of white LEDs

• Published in: Journal of alloys and compounds 2012-05, Vol.523, p.151-154
• Main Authors: Zhao, Cong, Zhu, Dachuan, Ma, Mingxing, Han, Tao, Tu, Mingjing
• Format: Article
• Language: English
• Subjects: Alloys; Co-precipitation; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cu; Doping; Electroluminescence; Electroluminescence spectra; Emission; Exact sciences and technology; Excitation; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other luminescence and radiative recombination; Other solid inorganic materials; Phosphors; Photoluminescence; Physics; Rendering; YAG
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2012.01.131

► Under the excitation of blue GaN chips, YAG:Ce3+,Cu+ phosphors exhibit brownish red. ► The peak of electroluminescence spectrum of YAG:Ce3+ developed into two peaks via doping Cu+ into the phosphors. ► We greatly improve the proportion of white LED light color. The optical properties of Cu+ and Ce3+ co-doped Y3Al5O12 synthesized by co-precipitation method are investigated in detail. Doping Cu+ ion into the YAG has little effect on the crystallized structure but the energy levels of Ce3+ ions have been changed. After doping with Cu+, the intensity of the broad emission band in the range of 580–700nm has been enhanced under the visible region excitation light (400–500nm) compared with that of undoped sample. Two broad emission bands of the electroluminescence spectra centered at around 540nm (yellow) and 630nm (red) are observed via a downconversion process under blue light (λem=460nm) excitation. Meanwhile, the red region of the electroluminescence spectra has been enlarged. Hence, Cu+ doping could be an effective method to enhance the red light proportion in white LEDs.