Emission colour tuning in KLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)phosphor  

作　　者：Janani K Gayathri E Vijayatha V Ramasubramanian S Thiyagarajan P 

机构地区：[1]Department of Science and Humanities,Nehru Institute of Technology,Kaliapuram,Thirumalayampalayam,Coimbatore,India [2]Department of Sciences,Amrita School of Physical Sciences,Amrita Vishwa Vidyapeetham,Coimbatore,India [3]Department of Physics,Anna University,Chennai,India

出　　处：《Journal of Rare Earths》2024年第1期57-65,I0002,共10页稀土学报（英文版）

摘　　要：KLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)(Ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction technique.For each of the Yb^(3+)/Er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and dopants.Upconversion luminescence emissions of green and red colour were detected for the synthesized phosphors.The changes in the upconverted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were investigated for the prepared phosphors.In the upconversion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prevalence of green emission.The rare-earth Er/Ho doped KYbF4shows strong red emission compared to other hosts.KYF_(4):Yb,Er/Ho exhibits relatively significant green upconve rsion emissions,while Yb,Er-doped KGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 mW.Downshifting photoluminescence studies and decay curve analysis were carried out using UV light excitation for the developed phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped KYbF_(4)sample.This study suggests a potential for colour tunability in the upconversion and downshifting emissions through host modifications to the fluoride phosphor.

关 键 词：Rare earths Energy transfer upconversion Downshifting Colour coordinates 

分 类 号：TQ422[化学工程]