The upconversion (UC) luminescence in sol-gel synthesized Li+, Zn2+, or Li+-Zn2+ codoped Y2O 3:Er3+ nanocrystals were investigated under the excitation of a 970 nm diode laser. Compared to undoped Y2O3:Er 3+ samples, proper doping of Li+-Zn2+ leads to an drastic increase of the UC luminescence centered at 560 nm by a factor of 28. The UC luminescence enhancement is a result of the increased lifetime of the intermediate state 4I11/2 (Er). The intensity ratio of the green over red emissions (green/red) is also affected by the codoping of Zn2+, Li+ and Li+-Zn2+ ions. Our results demonstrated that the Li+-Zn2+ codoping in Y 2O3:Er3+ phosphors produced remarkable enhancement of the UC luminescence and green/red ratio, making this nanocrystal a promising candidate for photonic and biological applications.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry