Electroluminescence in perovskite oxide nanocrystals

Chemically stable and easily printable inorganic surface-emitting devices are essential for portable, disposable, outdoor-safe, and wearable information display devices. However, inorganic electroluminescent devices with both chemical stability and printability have never been realized. We present the first report of an oxide-nanocrystalline powder-type self-emitting device without both capping and dispersion treatments. The Ca0.6Sr0.4TiO3:Pr nanocrystal was prepared by a hydrothermal synthesis method under supercritical water conditions. The red light-emitting electroluminescence intensity increased with an increase in the driving voltage. The starting electric field for electroluminescence generation is sufficiently low (6.9 × 104 V cm−1). The proposed electroluminescent device is achieved by minimizing the voids into the inside of the light-emitting layer and the interface between the light-emitting and insulating layers by using nanometer-sized oxide-phosphor-crystals. The oxide-nanocrystal electroluminescent device will be developed into future powder-type surface-emitting devices that may contribute in inventing numerous applications, such as outdoor information displays and wearable information terminals.