A Light Emitting Device with TiO2:Er3+/ZnO Heterostructure for Enhanced Near-Infrared Electroluminescence

Near-infrared (NIR) electroluminescence (EL) devices based on Er 3+ ions doped TiO 2 emitting layer have been fabricated by employing a facile sol–gel method. The effect of Er 3+ ion doping concentration on the EL performance of TiO 2 :Er 3+ thin film devices was investigated. Moreover, a novel device with the core of TiO 2 :1%Er 3+ /ZnO heterostructure was designed and fabricated. The EL performance of the device with optimized Er 3+ ion doping concentration and improved structure was significantly improved. The NIR EL-enabling voltage of the improved device is as low as ∼5 V. The attenuated concentration quenching effect and the ZnO film as an electron blocking layer should contribute to the improved EL performance of the optimized device.