Colorimetry and Characterization of The Sol-gel Derived Nanocrystaline Phosphor for Using in UV-LEDs

Sameie, H.; Salimi, R.; Sabbagh Alvani, A.A.; Sarabi, A. A.; Eivaz Mohammadloo, H.

Colorimetry and Characterization of The Sol-gel Derived Nanocrystaline Phosphor for Using in UV-LEDs

Authors

¹ Department of Polymer Engineering & Color Technology, Amirkabir University of Technology

² Color and Polymer Research Center, Amirkabir University of Technology

³ Department of Polymer Engineering and Color Technology, Amirkabir University of Technolog

Abstract

In this research, the europium Eu-activated SrZn2Si2O7 phosphors were successfully prepared by sol-gel method in reductive and oxidative atmospheres. Thermogravimetric-differential thermal analysis (TG-DTA), X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM and TEM) and photoluminescence (PL) spectra were used to characterize the resulting products. Obtained phosphor in reductive atmosphere is efficiently excited in the wavelength range of 350-390 nm which matches to a near UV (NUV) emitting InGaN chip and emits strong band blue light peaking at 481 nm with color coordination x=0.176, y=0.193 due to 4f65d1(2D)→4f7(8S7/2) transition of Eu2+ ions. Also, synthesized phosphor in oxidative atmosphere emits at approximately 480 and 600 nm that attributed to f-d transitions of Eu2+ and f-f electronic transitions of Eu3+, respectively. Finally, the crystallite size of the products was estimated about 30 nm by using Scherrer’s equation that this measurement was consistent with TEM observations.

Keywords