Electroluminescence Of Potassium Sodium Niobate/Polyimide Composite Films

Polyimide (PI) is one of the excellent comprehensive performance ofpolymer materials, so it is widely used in various fields. However, with thedevelopment of science and technology, this kind of polymer materials arebecoming more demanding. Therefore, in recent years, the polyimide as matrix ofcomposite material, has become a research focus in the academia and industry.In this article, prepared by in-situ polymerization method, respectively, thedoped potassium sodium niobate (KNN) content of0wt%,5wt%,10wt%,15,20wt%potassium sodium niobate/polyimide composite films (KNN/PI). And thecomposite membrane by X-ray diffraction (XRD), scanning electron microscope(sem), dielectric test respectively on the potassium sodium niobate/polyimidecomposite membrane structure, morphology, dielectric properties werecharacterized and analyzed. Test results show that the KNN dispersed evenly inthe PI matrix and stable, the dielectric properties of polyimide film got improvedsignificantly. Potassium sodium niobate/polyimide composite film dielectricconstant increased with the increase of the potassium sodium niobate particlesincreases, when the potassium sodium niobate particle mass fraction was20%,the dielectric constant is4.9(100Hz), the dielectric loss tangent value is less than0.025(100Hz), shows the good insulating properties.Then on the thin film electroluminescent (EL) experiment, the experimentalresults show that doping KNN had a greater influence on the breakdownthreshold of thin film, may be because the film defects after doping more make itbecome more easily breakdown. In300~350nm,450~500nm, found that thecharacteristic peak between550~600nm, doped potassium sodium niobateparticles found electroluminescent spectra after there is no obvious change.Finally, the reliability of research methods to help us analyze the reliabilityof the data, the paper used the two-parameter Weibull distribution method of the polyimide film were analyzed, of which the value of life and the value of the pre-breakdown field strength, when F (t)=0.5, t=164.9min; when F (E)=0.5, E=2.76MV/cm. Reliability of0.92and0.91, respectively.