Bifunctional Gd2O3:Er3+ particles with enhanced visible upconversion luminescence

- Gd2O3:Er3+/Li3+ particles with enhanced upconversion emission were synthesized.
- Strong enhancement of Gd2O3:Er3+/Li+ emission was induced by co-doped Li+ ions.
- It was suggested that Li+ can be used as a luminescence intensifier for phosphors.