Ce-doped TiO₂ Insulators in Thin Film Electroluminescent Devices

Abstract

Cerium-doped TiO 2 thin films have been prepared by reactive RF sputtering. At low Ce concentration, X-ray diffraction indicates that the films have the anatase structure. Ce concentrations higher than 1.2 at.% result in an amorphization of the film which remains stable up to 873 K. The TiO 2 electrical properties have been stabilized and improved by cerium doping, resulting in a lower conductivity (10 -9 Ω -1 m -1 ), a higher electrical breakdown strength (2 ×10 7 V/m), and a high value of the permittivity (45±5). The implementation of amorphous TiO 2 :Ce thin films as insulator layers in ZnS:Mn alternating current thin film electroluminescent devices (ACTFELD) results in a significant drop in the threshold operating voltage and a notable increase in the device brightness compared with ACTFELD containing Y 2 O 3 or BaTa 2 O 6 insulator layers. Rapid thermal annealing further improves the performance of the electroluminescent device.