Bright white light emitting Eu and Tb co-doped monodisperse In2O3 nanocrystals

Bright light emitting monodisperse In2-(x+y)EuxTbyO3 (x = 0.05, 0.1, 0.15, 0.2 and y = 0.05, 0.1, 0.15) nanocrystals were successfully synthesized by a versatile hot-injection colloidal route. The X-ray diffraction and X-ray photoelectron spectroscopy studies clearly showed that Eu and Tb were incorporated into the In2O3 lattice. Surface adsorbed NO3- and Cl- anions of Eu3+ and Tb3+ precursors assist the formation of flower like morphology through the oriented attachment process. Optical absorption spectra have been interpreted in terms of 4f -> 5d (Eu, Tb) and 2p(O) -> 5d (Eu, Tb) interband transitions. The observation of characteristic emission peaks related to Eu3+ and Tb3+ by indirect excitation suggests that In2O3 is an efficient sensitizer. Proper tuning of the compositions, 15% of Eu and 10% of Tb, gives the most intense white light and excellent chromaticity co-ordinates (0.35, 0.35). The shortening of lifetime with Eu and Tb doping improves the energy transfer from the host In2O3 to dopant Eu3+ and Tb3+ ions.