The near-infrared luminescence of Ca_(6)Ba(PO_(4))_(4)O∶Mn^(5+)is demonstrated and explained.When excited into the broad and strong absorption band that spans the 500-1000 nm spectral range,this phosphor provides an ...The near-infrared luminescence of Ca_(6)Ba(PO_(4))_(4)O∶Mn^(5+)is demonstrated and explained.When excited into the broad and strong absorption band that spans the 500-1000 nm spectral range,this phosphor provides an ultranarrow(FWHM=5 nm)emission centered at 1140 nm that originates from a spin-forbidden ^(1)E → ^(3)A_(2) transition with a 37.5%internal quantum efficiency and an excited-state lifetime of about 350 μs.We derived the crystal field and Racah parameters and calculated the appropriate Tanabe-Sugano diagram for this phosphor.We found that 1E emission quenches due to the thermally-assisted cross-over with the ^(3)T_(2) state and that the relatively high Debye temperature of 783 K of Ca_(6)Ba(PO_(4))_(4)O facilitates efficient emission.Since Ca_(6)Ba(PO_(4))_(4)O also provides efficient yellow emission of the Eu^(2+)dopant,we calculated and explained its electronic band structure,the partial and total density of states,effective Mulliken charges of all ions,elastic constants,Debye temperature,and vibrational spectra.Finally,we demonstrated the application of phosphor in a luminescence intensity ratio thermometry and obtained a relative sensitivity of 1.92%K^(-1) and a temperature resolution of 0.2 K in the range of physiological temperatures.展开更多
基金The authors from Serbia acknowledge funding from the Ministry of Education,Science,and Technological Development of the Republic of Serbia.M.D.D.recognizes the support from the Chinese National Foreign Experts Program for“Belt and Road Initiative"Innovative Talent Exchange(Grant No.DL2021035001L)M.G.B.thanks the support from the Program for Foreign Experts(Grant No.W2017011)offered by Chongqing University of Posts and Telecommunications+2 种基金Estonian Research Countil grant PUT PRG111,European Regional Development Fund(TK141),NCN project 2018/31/B/ST4/00924 and 2021/40/Q/ST5/00336C.G.M.acknowledges the support of the National Natural Science Foundation of China(Grant No.52161135110)China-Poland Intergovernmental Science and Technology Cooperation Program(Grant No.2020[15]/10).
文摘The near-infrared luminescence of Ca_(6)Ba(PO_(4))_(4)O∶Mn^(5+)is demonstrated and explained.When excited into the broad and strong absorption band that spans the 500-1000 nm spectral range,this phosphor provides an ultranarrow(FWHM=5 nm)emission centered at 1140 nm that originates from a spin-forbidden ^(1)E → ^(3)A_(2) transition with a 37.5%internal quantum efficiency and an excited-state lifetime of about 350 μs.We derived the crystal field and Racah parameters and calculated the appropriate Tanabe-Sugano diagram for this phosphor.We found that 1E emission quenches due to the thermally-assisted cross-over with the ^(3)T_(2) state and that the relatively high Debye temperature of 783 K of Ca_(6)Ba(PO_(4))_(4)O facilitates efficient emission.Since Ca_(6)Ba(PO_(4))_(4)O also provides efficient yellow emission of the Eu^(2+)dopant,we calculated and explained its electronic band structure,the partial and total density of states,effective Mulliken charges of all ions,elastic constants,Debye temperature,and vibrational spectra.Finally,we demonstrated the application of phosphor in a luminescence intensity ratio thermometry and obtained a relative sensitivity of 1.92%K^(-1) and a temperature resolution of 0.2 K in the range of physiological temperatures.
