Park Jin-Hyeok, Kim Chan-Hwi, Lee Ju-Hyeon, Kim Han-Ki
School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon-si, Gyeonggi-do 16419, Korea.
Micromachines (Basel). 2021 Feb 25;12(3):233. doi: 10.3390/mi12030233.
We fabricated transparent and flexible silicon oxycarbide (SiOC) hard coating (HC) films on a colorless polyimide substrate to use as cover window films for flexible and foldable displays using a reactive roll-to-roll (R2R) sputtering system at room temperature. At a SiOC thickness of 100 nm, the R2R-sputtered SiOC film showed a high optical transmittance of 87.43% at a visible range of 400 to 800 nm. The R2R-sputtered SiOC films also demonstrated outstanding flexibility, which is a key requirement of foldable and flexible displays. There were no cracks or surface defects on the SiOC films, even after bending (static folding), folding (dynamic folding), twisting, and rolling tests. Furthermore, the R2R-sputtered SiOC film showed good scratch resistance in a pencil hardness test (550 g) and steel wool test under a load of 250 g. To test the impact protection ability, we compared the performance of thin-film heaters (TFHs) and oxide-semiconductor-based thin-film transistors (TFTs) with and without SiOC cover films. The similar performance of the TFHs and TFTs with the SiOC cover window films demonstrate that the R2R-sputtered SiOC films offer promising cover window films for the next generation of flexible or foldable displays.
我们在无色聚酰亚胺基板上制备了透明且柔性的碳氧化硅（SiOC）硬涂层（HC）薄膜，以便在室温下使用反应性卷对卷（R2R）溅射系统将其用作柔性和可折叠显示器的覆盖窗薄膜。当SiOC厚度为100 nm时，R2R溅射的SiOC薄膜在400至800 nm的可见光范围内显示出87.43%的高光学透过率。R2R溅射的SiOC薄膜还表现出出色的柔韧性，这是可折叠和柔性显示器的一项关键要求。即使经过弯曲（静态折叠）、折叠（动态折叠）、扭曲和滚动测试后，SiOC薄膜上也没有裂纹或表面缺陷。此外，R2R溅射的SiOC薄膜在铅笔硬度测试（550 g）和250 g负载下的钢丝绒测试中表现出良好的耐刮性。为了测试抗冲击保护能力，我们比较了有无SiOC覆盖膜的薄膜加热器（TFH）和基于氧化物半导体的薄膜晶体管（TFT）的性能。带有SiOC覆盖窗薄膜的TFH和TFT的相似性能表明，R2R溅射的SiOC薄膜为下一代柔性或可折叠显示器提供了有前景的覆盖窗薄膜。
