Primary thermometers based on sol–gel upconverting Er3+/Yb3+ co-doped yttrium tantalates with high upconversion quantum yield and emission color tunability - Ribeiro, Fernanda Hediger Borges; Martins, Joana Costa; Caixeta, Fábio José; Pereira, Rafael Ramiro; Carlos, Luis Dias; Ferreira, Rute A. S.; Gonçalves, Rogéria Rocha (Journal of Sol-Gel Science and Technology, 2022)