为了克服传统的原子层深沉积反应温度高于有机材料的玻璃化温度对有机电致发光器件性能产生破坏的缺点, 使用低温原子层沉积的方法沉积了Al2O3薄膜, 成功地实现了对OLED的薄膜封装。实验中为了抑制环境温度对ALD薄膜均匀性的影响, 增加了每个反应周期的抽气时间, 从而可以充分地排出反应副产物, 抑制了空位的形成, 使得薄膜具有较高的均匀性和致密性。微观形貌分析、钙测试以及寿命测试表明, 通过增加ALD的PGT, 低温制备的薄膜与高温制备的薄膜的均匀性差别较小, 且制备过程对OLED器件的光电性能无明显影响。低温制备的薄膜水汽透过率(WVTR)可以达到8.6×10-4 g/(m2·d),能够有效地提高有机电致发光器件的寿命。

In order to avoid the damage of high reaction temperature to OLEDs, the low-temperature atomic layer deposition (ALD) process was introduced to deposite Al2O3 film for the encapsulation of OLEDs. However, the low temperature condition would decrease the uniformity of the film. In order to suppress the generating of vacancy, the pumping gas time(PGT) was increased during each cycle to discharge the products adequately. The micrographs, calcium test and lifetime test of OLEDs show that the film deposited at low temperature is almost the same with that deposited at high temperature, and the temperature effect to OLEDs is not negligible. The water vapor transmission rate (WVTR) of the film can reach to 8.6×10-4 g/(m2·d), so the lifetime of the device with the encapsulation layer can be increased effectively.