Low-voltage electroluminescence of europium in zinc oxide thin films

Europium(III)-containing zinc oxide thin films (1, 5, 8, and 10at.%) were prepared from Pechini’s solution and used as active layers in thin-film electroluminescent devices. By applying a low bias steady state voltage (10–50V) it was possible to observe electroluminescence of the device. By increasing the rate Eu3+∕Zn2+ the relative intensity of emission from the dopand Eu3+ ions increases, while the relative intensity of emission from the zinc oxide (ZnO) matrix decreases. This leads to ZnO:Eu3+ (10at.%) thin-film electroluminescent devices with low-voltage operation and high pure color.