Using zinc acetate and europium chloride solution as precursor.ZnO:Eu thin films were deposited on the ITO glass substrate by the ultrasonic spray pyrolysis(USP) method.The morphologies,crystal strustures and optical properties were investigated by using scanning electro microscopy(SEM),X-ray diffraction(XRD) and photoluminescence(PL).The SEM results indicate that the USP method can obtain compact and uniform ZnO:Eu thin films with nanocrystal diameters about 200-250 nm.The XRD patterns reveal t...