Enhancement of white light emission from novel Ca3Y2Si3O12:Dy3+ phosphors with Ce3+ ion codoping

Abstract

The luminescent properties of the Ce3+ or Dy3+ singly doped and Ce3+/Dy3+ codoped in Ca3Y2Si3O12 novel phosphors were investigated, which are prepared by a sol-gel method. Ce3+ doped phosphor showed a brighter and broader violet-blue color emission band with a maximum peak centered at 389 nm, which is attributed to the parity and spin allowed 5d–4f transition. Photoluminescence spectra reveals that the white color emission is originated from the mixtures of two characteristic emission bands of Dy3+ ion, viz., the 473 nm blue emission (F49/2-H615/2) and the 580 nm yellow emission (F49/2-H613/2). codoping of Ce3+ has enhanced the luminescence of Dy3+ quite significantly upon the UV excitation wavelength (242 nm) and the optimized codopant concentration of Ce3+ is found to be 3 mol %. The mechanism involved in the energy transfer between Ce3+ and Dy3+ has been elucidated by an energy level diagram. The structure and morphology of the prepared samples have been analyzed by x-ray diffraction and transmission electron microscope.

Blue-yellow photoluminescence from Ce3+→Dy3+ energy transfer in HfO2:Ce3+:Dy3+ films deposited by ultrasonic spray pyrolysis

“…Recently white light emission upon UV excitation was reported in CeCl 3 /TbCl 3 /MnCl 2 doped hafnium oxide films through an efficient sensitization of Tb 3+ and Mn 2+ ions by Ce 3+ ions [4]. White light emission has been also attained in Ca 3 Y 2 Si 3 O 12 [5] and Li 2 CaGeO 4 [6] phosphors and oxyfluoride glass ceramics [7,8] codoped with Ce 3+ and Dy 3+ ions. In these materials white emission is originated from dysprosium through the mixture of its blue ( 4 F 9/2 → 6 H 15/2 ) and yellow ( 4 F 9/2 → 6 H 13/2 ) emissions, which are significantly enhanced through an efficient Dy 3+ sensitization by Ce 3+ ions excited at UV wavelengths.…”

“…Ce 3+ ions exhibit broad absorption bands in the UV, so that they can be easily excited by AlGaN/GaN-based LEDs [4]. The intense broad absorption band of Ce 3+ ions is a consequence of their 4f → 5d parity allowed electric dipole transitions, so that in co-doped materials such ions act as good sensitizers, transferring a part of their excitation energy to activator ions such as Tb 3+ [4,[9][10][11], Mn 2+ [10][11][12][13][14][15] and Dy 3+ [5][6][7][8]11].…”

The effect of doping La3+ on structure and luminescent properties of Sr2SiO4:Eu2+ phosphors

“…As the key material for preparing w-LEDs, many kinds of phosphors have been explored [2][3][4][5][6][7][8][9][10][11], such as silicates, aluminates, sulfides, phosphates, nitrogen-oxides, oxides and nitrides. Comparing with other phosphors, silicate phosphor has many advantages, such as abundant crystal structure, excellent thermal stability, and low sintering temperature [12][13][14][15].…”

Excitation wavelength dependent luminescence properties for Eu3+-activated Ba2Gd2Si4O13 phosphor

“…To our knowledge, silicates are considered as suitable host matrixes for phosphors due to the characteristics of high physical and chemical stability, water-resistant property, stable crystal structure, and excellent optical properties [8,9] [10]. The luminescence properties have been paid close attention in the previous work [11,12].…”