Optical properties of Er3+, Yb3+ co-doped calcium zirconate phosphor and temperature sensing efficiency: Effect of alkali ions (Li+, Na+ and K+). (August 2018)

• Record Type: Journal Article
• Authors: Maurya, A.; Bahadur, A.; Dwivedi, A.; Choudhary, A.K.; Yadav, T.P.; Vishwakarma, P.K.; Rai, S.B.
• Is Part Of: Journal of physics and chemistry of solids. Volume 119(2018)
• Page Start: 228
• Page End: 237
• Publication Date: 2018-08
• Subjects: Rare earth -- Calcium zirconate phosphor -- Alkali ions -- Upconversion -- Temperature sensor; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2018.04.004
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: The Er 3+ /Yb 3+ co-doped calcium zirconate phosphors have been synthesized through solid state reaction method. The structural characterizations confirm the crystalline nature of the phosphor. The Er 3+, Yb 3+ co-doped phosphor emits intense green emission centered at 523 and 544 nm due to the 2 H11/2 → 4 I15/2 and 4 S3/2 → 4 I15/2 transitions, respectively and weak red emission at 662 nm due to 4 F9/2 → 4 I15/2 transition of Er 3+ on excitation with 976 nm radiation. The emission intensity of the green band dominates over the red band. When the alkali ions (Li +, Na +, K + ) are added in the Er 3+ /Yb 3+ co-doped phosphor, the emission intensities of bands enhance significantly. The fluorescence intensity ratio correspond to 523 and 544 nm peaks at different temperatures have been obtained which confirm the temperature sensing ability of the samples. In presence of alkali ions, the temperature sensor sensitivity increases and is maximum for K + co-doped phosphor. It is found that the energy gap between 2 H11/2 and 4 S3/2 levels increases with crystallinity in order of K + >Na + >Li + > without alkali ion. Thus, the Li +, Na + and K + incorporated Er 3+, Yb 3+ co-doped calcium zirconate phosphor may be useful for photonic devices and temperature sensor. Graphical abstract: Highlights: ➢ The Er 3+ /Yb 3+ /R + (R + = Li +, Na +, K + ) co-doped CaZrO3 phosphors have been synthesized by solid state reaction method. ➢ The SEM image shows more sharp grain boundary and bigger particle size and the agglomeration of grains is decreased in the presence of alkali ions. ➢ The emission intensity increases with addition of alkali ions due to increase in crystallinity and asymmetry in crystal field. ➢ In presence of alkali ions, the increase in emission intensity causes the increase in temperature sensor sensitivity which is maximum for K + co-doped phosphor.