Ultraviolet upconversion luminescence enhancement in Yb3+/Er3+-codoped Y2O3 nanocrystals induced by tridoping with Li+ ions

Enhancement of upconversion luminescence of Y2O3:Er3+ nanocrystals by codoping Li+–Zn2+

“…One can see that the Y 2 O 3 nanocrystals have nearly spherical shape with an average diameter of about 50 nm. The nanocrystals doped with Li + ions have similar morphology [17]. Fig.…”

“…The nanocrystals are still in cubic phase, and the XRD pattern matches well to the standard pattern of Y 2 O 3 (JCPDS 89-5592). This can be understood because both Li + and Zn 2+ can easily get into the host lattice owing to their small ionic radii [12,17]. So the main crystal phase of Y 2 O 3 has not been affected.…”

“…Under the excitation of a 970 nm diode laser, the dominant UC luminescence of Y 2 O 3 :Er 3+ nanocrystals are green and red UC emissions. Recently, it was found that codoping Li + ions can enhance UC emission and increase the intensity ratio of the green over red emissions (green/red) of Er 3+ doped oxides [12][13]17,18].…”

Femtosecond-pulse laser-ablation-induced synthesis and improved emission properties of ultrafine Y2O3:Er3+, Yb3+ nanoparticles with reduced nonradiative relaxation

“…6, the experimental curves for green and red emission display a strong fit to a double exponential function. Generally, the fast-decay component arises from the emitting-level lifetime, and the long component is due to seeding from the intermediate states of 4 I 11/2 , 4 I 13/2 (Er 3þ ), or 2 F 5/2 (Yb 3þ ) [9]. For the Er 3þ -single-doped samples, the slower green emission component was almost equal to the 4 I 11/2 -level lifetime and the slower red emission component almost equated to the 4 I 13/2 -level lifetime.…”

Ultraviolet emissions from Gd3+ ions excited by energy transfer from Ho3+ ions

“…To produce UV lasers, continuous population of the corresponding high energy states is the key. Frequency upconversion (UC) by means of rare-earth ions' ladder-like energy levels is a promising technique to populate such high energy states, considering the availability of ample high-power infrared (IR) and visible diode lasers [4][5][6][7]. Recently, the UV UC emissions of Er 3+ , Tm 3+ , Pr 3+ , Tb 3+ and Ho 3+ ions have been studied extensively [8][9][10][11][12].…”