Controllable white light emission from Dy3+–Eu3+ co-doped KCaBO3 phosphor

KCa4(BO3)3:Ln3+ (Ln = Dy, Eu, Tb) phosphors for near UV excited white–light–emitting diodes

“…12,13 However, despite many advantages, the final phosphor product suffers from complexities associated with the combination of several phosphors used in the fabrication and its significant degradation during heating, which reduce the lifetime and efficiency of WLEDs. 10,11,14 The pursuit in this direction has led to identify new class of phosphors having broadband near white emitting properties based on oxides, [15][16][17][18] oxyfluorides, 19,20 nitrides, 21,22 oxynitrides, [23][24][25] sulfides 26,27 and halides. 28,29 Among all, the oxyfluoride (for example: Sr 2.975-x -Ba x Ce 0.025 AlO 4 F) phosphors have been seen with alacrity as the most efficient matrix for photoluminescence due to their low phonon energy.…”

“…20 Therefore single-host broad band emitting phosphors need to be developed for low-cost W-LEDs with improved chemical and thermal stability better reproducibility and a simpler fabrication process. 10,11 With the above mentioned perspectives, the present article focuses on studying the influence of rare-earth doping/co-doping on the luminescence properties of borate based phosphors. Owing to their simple and low-cost fabrication along with high thermal and chemical stability as well as transparency over a wide spectral range (beginning from UV and extending into visible) 5,11 borate hosts are considered as potential candidates for many potential optoelectronic applications, particularly in the field of laser science and technology.…”

“…Owing to their simple and low-cost fabrication along with high thermal and chemical stability as well as transparency over a wide spectral range (beginning from UV and extending into visible) 5,11 borate hosts are considered as potential candidates for many potential optoelectronic applications, particularly in the field of laser science and technology. 11 35 and NaSrBO 3 :Ce 3+ . 5 The aim of the present research is to develop borate (containing planar [BO 3 ] 3-groups) based phosphors having the quality of near white light emission, since borate hosts exhibited excellent thermal stability over the commercial YAG host, 5 and they are less moisture sensitive in nature than the usual oxyfluoride hosts.…”

“…5,20 Very recently, we have successfully demonstrated promising near white-light emission from KCaBO 3 :Dy 3+ ,Eu 3+ phosphor upon blue excitation. 11 The KCaBO 3 systems are found to be attractive since the enhanced luminescence properties are observed due to the occupation of large concentrations of DY 3+ /Eu 3+ ions into the Ca 2+ ions by the preferential charge-compensation mechanism of 2Ca 2+ = Dy 3+ /Eu 3+ + K + .…”

“…Particularly, the Dy 3+ ion emission show strong crystal field effects, therefore intensity of hypersensitive yellow color emission from the transition 4 F 9/2 → 6 H 13/2 is strongly influenced by the host environment, compared to the other non-hypersensitive emission band 4 F 9/2 → 6 H 15/2 . 11,37,38 Hence, it is interesting to observe such host matrix influence on the near-white light generation from Dy 3+ -doped phosphors directly by fine tuning the ratio of these yellow and blue prominent emission intensities. 37,38 We have also developed Eu 3+ and Tb 3+ singly and co-doped systems for red and green emission components for the generation of white-light.…”