蓝色有机电致发光材料OXD-7的合成及性能

重点研究了蓝色有机电致发光材料OXD-7的合成路线及提高产率的方法,并用自行设计加工的升华提纯装置进行两次OXD-7的升华提纯,可使产物纯度达到99.2%。通过真空镀膜制作出结构为ITO/CuPc/NPB/OXD-7/Alq₃/Mg-Ag/Al的器件,器件采用透明ITO导电玻璃作正极,依次真空蒸镀酞菁铜、NPB、OXD-7、Alq₃、Mg-Ag电极,最后在合金电极上覆盖一层很薄Al膜。膜厚由频率震荡计监测,测试了器件的光电性能以及寿命,研究并讨论了材料的纯度对器件寿命的影响。

Synthesis and Properties of a Blue Organic Electroluminescent Material

The synthesis method of OXD-7 was studied chiefly.Its synthesis step as follows: 1.Ethyl 4-tert-butylbenzoate can be prepared by the esterification reaction of 4-tert-butylbenzonic acid and ethyl alcohol,then it was reacted with hydration hydrazine to get 4-(t-butyl)benzoyl hydrazine;2.m-phthaloyl chloride was prepared by the reflux reaction of isophthalic Acid and thionyl chloride;3.4-tert-butyl benzoyl hydrazine was added to the synthesized m-phthaloyl chloride.The mixture was(allowed) to react at 80℃ for 2 h,then the mixture was cooled and then poured into ice-water.The precipitate was filtered and washed with water,dry in 100℃,the previous compound of OXD-7 was prepared.Finally,the previous compound of OXD-7 was put into the three-necked bottle,POCl₃ and PCl₅ was added,heats to reflux for 5 h,the phosphorous oxychloride was removed by the distillation under a reduced pressure,filters,the residue was washed with water and recrystallized two times from ethyl alcohol to give 11.2 g of OXD-7,the purity is 97.2% by HPLC.The sublimation of OXD-7 was executed under the pressure of 35 Pa and the(temperature) of 300℃ used the sublimation system designed by ourselves.After the sublimation,the purity of OXD-7 is 99.2%,the melting point is 241.5℃.A blue organic electroluminescent device was fabricated and its structure is ITO/CuPu/NPB/OXD-7/Alq₃/Mg-Ag/Al.An indium-tin-oxide coated glass substrate (anode substrate) was sequentially washed in a cleaning solution,rinsed in deionized water and dried.Copper phthalocyanine(150),N,N′-bis-(1-naphthyl)-N,N′-diphenyl benzidine(600),OXD-7,alumium-tris-8-hydroxyquinoline(350)were vapor deposited in turn on the ITO glass,then Mg-Ag alloy was vapor deposited as the anode,finally,metal aluminum was vapor deposited onto the Mg-Ag alloy as the protecting layer.The device was packaged in a dry glove box full of(nitrogen) for protection against ambient environment.The photoelectric property and life-time of OXD-7 were tested.The influence of the material purity to the lifetime and the brightness was studied and discussed.Under 8 V drive voltage,the device gives a blue emission peaked at 472 nm,the maximal brightness is about 456 cd/m²,the CIE coordinate of the emission color is x=0.144 4,y=0.098 1.