Luminescence Characteristics and Annealing Effect of Tb-Doped AlBNO Films for Inorganic Electroluminescence Devices

Inorganic electroluminescence (EL) devices have attracted attention because of their application in low-power-consumption displays. However, the operating voltage of inorganic EL devices is very high. We have investigated AlBNO films as host materials of the luminescence layer to lower the operating voltage. Moreover, the investigation used Tb as the luminescence center because Tb 3+ ions show green luminescence that has a high luminous coefficient. Tb-doped AlBNO films were deposited by RF magnetron sputtering. Cathodoluminescence and photoluminescence show the luminescence due to f–f transition of Tb 3+ ions. The luminescence can be attributed to both the energy transfer from the host material to the Tb 3+ ions and the direct excitation of Tb 3+ ions. In addition, we achieved a drastic increase in the luminescence by an annealing treatment due to an increase in Tb 3+ ions and the homogeneous dispersion of Tb atoms. Therefore, AlBNO films could be used for inorganic EL devices.