Intra-4f transitions-induced red emission in ZnO-Eu2O3 ceramic

In this study, we report the phenomenon of radioluminescence (RL) in ZnO-Eu2O3 binary oxide ceramics. RL results showed the presence of a wide emission band in the visible region centered at 530 nm and a well-defined peak at 610 nm. The emission band is originated due to energy levels created by intrinsic defects inside the bandgap of ZnO. On the other hand, the peak is related to the 5D0 → 7F2 transition in the Eu3+ ion, which is possible through the energy transfer mechanism between ZnO and Eu2O3. The RL spectra presented a linear behavior as a function of the electric current or voltage applied in the X-ray tube. •Radioluminescence in ZnO-Eu2O3 binary system ceramics•Energy transfer mechanism between ZnO and Eu2O3•Coexistence of green and red emissions•Radioluminescence with linear behavior as a function of the electric current or voltage in the X-ray tube•The system ZnO-Eu2O3 represents an attractive candidate for X-ray sensor