Photoluminescence investigation in tungstate based materials

Tungstate based phosphor materials are very much promising because of their emerging application in various fields including optoelectronic devices, display devices, sensors, anti-counterfeiting, bioimaging, etc. In the present work, Er3+: MgWO4 phosphors have been synthesized via conventional solid state reaction method. The phase formation of the phosphors is confirmed by X-ray diffraction analysis. The vibrational modes and phonon frequency of the prepared phosphors have been investigated by FTIR analysis. Upon 980 nm diode laser excitation, the Er3+: MgWO4 phosphors exhibit several upconversion (UC) emission bands peaking at similar to 489 nm, similar to 523 nm, similar to 545 nm, similar to 655 nm and similar to 800 nm. The pump power dependent UC emission study of the Er3+: MgWO4 phosphors has been carried out. The responsible mechanisms for the UC emission in the present phosphors have been explained by schematic energy level diagram. The reason behind the concentration quenching phenomenon has been discussed. The CIE chromaticity coordinates of the present phosphors have been calculated using GoCIE software. Thus, the synthesized phosphors can be suitably applicable in NIR to visible upconverter, temperature sensing, security ink and solid state lighting purposes. (C) 2019 Elsevier Ltd. All rights reserved.