Publication Date:
2017-04-22
Description:
A series of novel SrLu 2 O 4 : x Ho 3+ , y Yb 3+ phosphors ( x =0.005-0.05, y =0.1-0.6) were synthesized by a simple solid-state reaction method. The phase purity, morphology, and upconversion luminescence were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. The doping concentrations and sintering temperature were optimized to be x =0.01, y =0.5 and T =1400°C to obtain the strongest emission intensity. Under 980 nm laser diode excitation, the SrLu 2 O 4 :Ho 3+ , Yb 3+ phosphors exhibit intense green upconversion (UC) emission band centered at 541 nm ( 5 F 4 , 5 S 2 5 I 8 ) and weak red emission peaked at 673 nm ( 5 F 5 5 I 8 ). Under different pump-power excitation, the UC luminescence can be finely tuned from yellow-green to green light region to some extent. Based on energy level diagram, the energy-transfer mechanisms are investigated in detail according to the analysis of pump-power dependence and luminescence decay curves. The energy-transfer mechanisms for green and red UC emissions can be determined to be two-photon absorption processes. Compared with commercial NaYF 4 :Er 3+ , Yb 3+ and common Y 2 O 3 :Ho 3+ , Yb 3+ phosphors, the SrLu 1.49 Ho 0.01 Yb 0.5 O 4 sample shows good color monochromaticity and relatively high UC luminescence intensity. The results imply that SrLu 2 O 4 :Ho 3+ , Yb 3+ can be a good candidate for green UC material in display fields.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
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