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摘要
From the view point of practical application, one thorny problem in organic light emitting diode (OLED) devices is how to protect the inner materials from being eroded by oxygen and moisture, and to undertake sufficient long-term stability. Alq(3) is the earliest and widely used organometallic material as an electron transport layer and light emitting layer in OLED, undoubtedly, improving its photochemical stability via coating it with materials that possess anti-oxygen and anti-water characters is one of cost-effective ways. Motivated by this, here, we demonstrate one pot synthesis of Alq(3)@SiO2 with uniform SiO2 covering. To obtain the optimized core-shell Alq(3)@SiO2 particle, a mixture of 8-hydroxyquinoline (6 mmol), 1 mL Et3N and 2 mL deionized water was dissolved in 120 mL ethanol and then heated to 70 degrees C, a solution of Al-2(SO4)(3)center dot 18H(2)O (1 mmol) in 5 mL water and a solution of tetraethylorthosilicate (TEOS) (2 mmol) in 5 mL ethanol were added dropwise at the same time, respectively. The mixture was allowed to react at 70 degrees C for about 5 h. Then, a green precipitate was obtained, and purified by washing with water and ethanol. The scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed to characterize the morphology of the as-synthesized Alq(3)@SiO2 particles, which exhibited better results than previous reported. From the measurement of UV-Vis and PL spectra we can see the Alq(3)@SiO2 we have produced exhibited similar absorption and emission profile compared to pristine Alq(3), which is beneficial for future application in OLED because it is almost not change the optical property of Alq(3). The prepared principle of Alq(3)@SiO2 can be assigned to the plausible Cage Effect of Et3N embraced Lewis acid Alq(3), and a further Et3N catalytic hydrolysis of TEOS to produce SiO2 on the surface of formed Alq(3). Note that Et3N used in this case is also acted as Alq(3) morphology protective agent during TEOS hydrolysis. This work provides a facile and large scale preparation of Alq(3)@SiO2 for future improving the long-term stability of OLED devices.
- 出版日期2013-7-15
- 单位太原理工大学
