Single-phased white-light-emitting NaCaBO₃:Ce³⁺,Tb³⁺,Mn²⁺phosphors for LED applications

Abstract

A series of NaCaBO3:Ce(3+),Tb(3+),Mn(2+) borate phosphors were prepared via a high-temperature solid-state reaction. The obtained phosphors exhibit a strong excitation band between 250 and 400 nm, matching well with the dominant emission band of a NUV light-emitting-diode (LED) chip. The phosphors can generate light from blue to green, and from blue to red by Ce(3+)→Tb(3+) and Ce(3+)→Mn(2+), respectively. Furthermore, a wide-range-tunable white light emission was obtained by precisely controlling the contents of Ce(3+), Mn(2+), Tb(3+). The results show that this phosphor has potential applications as a single-phased phosphor for NUV white LEDs.

The synthesis and photoluminescence of a single-phased white-emitting NaAlSiO 4 : Ce 3+ , Mn 2+ phosphor for WLEDs

“…2a exhibits the PLE and PL spectra of Na 0.97 AlSiO 4 : 0.03Ce 3+ . Monitored at 430 nm, the PLE spectrum clearly demonstrates that there are two absorption bands, peaked at 290 and 350 nm, which assigned to the electron transitions of Ce 3+ from the 2 F 5/2 ground state to the different components of excited 5d states split by the crystal field [18]. Under the excitation of 350 nm, the PL spectrum exhibits a broad nonsymmetrical band in the wavelength ranged at 350-600 nm with a peak centered at about 430 nm, which is attributed to the transition from the 5d level to the ground state of Ce 3+ .…”

“…The white light is usually attributed to different activators or one kind of activator at different crystal sites [9][10][11][12]. Recently, the single-phased color-tunable with white light-emitting phosphors have been obtained by co-doping Ce 3+ and Mn 2+ in proper hosts, such as Ca 2 SrAl 2 O 6 [8], NaCaBO 3 [13], and Ca 2 Gd 8 (SiO 4 ) 6 O 2 [14]. As is well known that silicates have the advantages such as high chemical-physical stability and various crystal structures, which can be good candidates for WLEDs applications.…”

Enhanced luminescence properties and energy transfer in Ce3+ and Tb3+ co-doped NaCaBO3 phosphor

“…Among many orthoborates, NaCaBO 3 (NCBO) with orthorhombic structure was firstly reported by Wu et al [12]. Recently, blue-emitting NaCaBO 3 : Ce 3 þ and tri-chromatic NaCaBO 3 : Ce 3 þ , Tb 3 þ , Mn 2 þ phosphor was reported by our group [13]. However, due to the complicated corporative energy transfer process of tri-doped system, the detailed Ce 3 þ -Tb 3 þ energy transfer (ET) mechanism was not investigated in the previous study.…”

Chemical behavior and spectroscopic properties of rare earth borates in glazes

“…We should also mention here recent investigations on alkali and alkaline earth borate phases (e.g. of compositions NaSr 4 (BO 3 ) 3 , Ba 3 Y 2 (BO 3 ) 4 , NaCaBO 3 ) doped with Ce 3 þ , Tb 3 þ and Mn 2 þ , the latter of which displayed efficiencies of the green emission of 36% under 347 nm excitation [14][15][16]. Due to the still moderate quantum yields and higher energy excitation maxima given for NaCaBO 3 , as well as of the undiluted CeBO 3 :Tb, we decided to focus on borate compositions comprising Y 3 þ , Ce 3 þ and Tb 3 þ .…”