Chen Zheng, Wang Zhenyu, Zhou Yibin, Zhang Jian, Li Ze, Li Chuannan, Chen Ping, Duan Yu
Opt Express. 2021 Oct 11;29(21):33077-33085. doi: 10.1364/OE.422253.
The laminated structure of thin-film encapsulation (TFE) plays an important role for the reliability of organic light-emitting devices (OLEDs). In previous studies of TFE-structures, only the density of the films and the gas-barrier properties were taken into account, while a potential internal stress in the film was largely neglected. Internal stress issues can lead to cracks, warping, and delamination, which affect the performance of the encapsulation layer significantly. Finding ways to eliminate or perhaps utilize potential internal stresses of these films could have substantial benefits for future OLEDs. This study is at the forefront of the stress-related properties of TFE in conjunction with optoelectronic devices. We perform a moisture-barrier test of a fabricated encapsulated laminated structure (Si/50 nm SiON/50nmSiO/900 nm SiON. The 50 nm SiON buffer-layer was deposited (via chemical vapor deposition) to prevent the delamination and peeling between the SiO film and the OLEDs because of the high stress acting on the SiO layer. The water-vapor transmission rate of the laminated structure is below 5×10 g/m·d at 38°C and 100% relative humidity. The concept of a laminated TFE-structure has a great application potential for future flexible and bendable organic optoelectronics.
薄膜封装（TFE）的层压结构对有机发光器件（OLED）的可靠性起着重要作用。在之前对TFE结构的研究中，仅考虑了薄膜的密度和气密性，而薄膜中潜在的内应力在很大程度上被忽视了。内应力问题会导致裂纹、翘曲和分层，这会显著影响封装层的性能。找到消除或利用这些薄膜潜在内应力的方法可能会给未来的OLED带来巨大益处。这项研究处于TFE与光电器件相关应力特性研究的前沿。我们对制备的封装层压结构（Si/50nm SiON/50nm SiO/900nm SiON）进行了防潮测试。沉积50nm的SiON缓冲层（通过化学气相沉积）是为了防止由于作用在SiO层上的高应力导致SiO薄膜与OLED之间出现分层和剥离现象。该层压结构在38°C和100%相对湿度下的水蒸气透过率低于5×10 g/m·d。层压TFE结构的概念在未来的柔性和可弯曲有机光电子学领域具有巨大的应用潜力。
