Ultraviolet and Visible Upconversion Emissions in Er3+-Yb3+ Doped Titanium Dioxide Nanopowder under the 980 nm Laser Diode Excitation

Er3+-Yb3+ co-doped titanium dioxide upconversion nanoparticleswere synthesized by sol-gel method. White upconversion emissions were observed after excitation of nanoparticles with 980 urn Near-Infrared laser diode. Upconversion emissions consist, of red (640-690 ma), green (520-570 ma), and blue (108 um) emissions. Ultraviolet pC0:11 versicm emissions were also detected with wavelength about, 210 am. Ultraviolet emissions are probably the results of relaxation from I-2(13/2) (220 win) and L-2(15/2) (210 rim) states to I-4(15/7).-Visible and ultraviolet emissions of these nanopartides can be used in photodynamic therapy. High penetration of Near-Infrared light into the body tissue makes these nanoparticles amopriate for aimi tutors in deeper tissues in comparison with older methods of pliotodynamic therapy. (C) 2017 Sharif University. of Technology. All rights reserved.