Diamine的光、电性质及其在有机薄膜电致发光器件中的应用

合成了芳香族二胺类衍生物(diamine),测定了它的光、电性质.制备了diamine作为空穴传输层的二层结构有机薄膜电致发光器件,使器件的发光亮度相对单层器件有了很大的提高.并用不同区域掺杂的方法,探讨了电致发光机理.分析、讨论了激子的形成和复合区域,较好地解释了单、双层器件的不同的电流电压关系和不同的亮度电压关系.从激子的扩散方程出发,对双层掺杂器件的发光强度比数据进行了拟合,确证了激子的扩散模式.

THE OPTIC AND ELECTRIC PROPERTIES OF DIAMINE AND ITS APPLICATION IN ORGANIC TFEL DEVICE

Diamine, a derivative of triphenyldiamine, was synthesized. The absorption and photoluminescent properties of the diamine thin film were investigated. Its charge conductivity was measured also. A type of organic thin film electroluminescent device with two layer structure, using diamine as hole transporting material, Alq3 as emitting material, was fabricated.It was found that when diamine was used the EL brightness of device is increased by a order of magnitude, though the electrical current passing through the device is less than half at the same applied voltage,By analysing the change of the EL spectra of the device with the laser dye DCM doped thinner layer at different possition in the emitting film, the mechanism of electroluminescence of two type devices has been studied.It is showed that the molecular excitons are generated at the interface of diamine and Alq3 layer, diffused toward the Al cathode and formed a exponential distribution in two-layer device, while in single layer device, the excitons are generated at a narrow zone in Alq3 layer, 30nm apart of ITO layer,diffused in both directions and formed a peak. A luminescent model is built up and the experimental results are well explained. The diffusion length is evaluated as 21nm according to an equation derived from diffusion law.