Abstract
Sol-gel derived nano-glass-ceramics with composition 95SiO2-5BaY0.78-xGdxYb0.2Tm0.02F5, where x = 0, 0.2, 0.4, 0.6 and 0.78, were obtained after adequate thermal treatments of precursor glasses. X-ray diffraction, transmission electron microscope and energy dispersive X-ray spectroscopy, confirmed the precipitation and distribution of nanocrystals, with sizes around 10–13 nm, in an amorphous silica network. Under excitation at 980 nm, along with blue, red and NIR characteristic up-conversion emissions of Tm3+ ions, intense UV up-conversion emissions coming from 1I6 and 1D2 levels of Tm3+ ions were also observed in all the studied samples. Additionally, when substituting Y3+ by Gd3+ ions, UV up-conversion emissions coming from Gd3+ ions, along with a reduction of the UV up-conversion emissions of Tm3+ ions, were observed, involving an energy transfer process from Yb3+/Tm3+ systems to Gd3+ ions. UC mechanisms and energy transfer processes were confirmed by transient emission and pump power measurements. Moreover, power dependence analysis revealed saturation effects in all up-conversion emissions, even at low pump power. Results suggest that these highly efficient up-conversion nano-glass-ceramics present potential applications as UV-blue solid state laser materials and solid state lighting.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
