Chen Zhaolong, Liu Zhiqiang, Wei Tongbo, Yang Shenyuan, Dou Zhipeng, Wang Yunyu, Ci Haina, Chang Hongliang, Qi Yue, Yan Jianchang, Wang Junxi, Zhang Yanfeng, Gao Peng, Li Jinmin, Liu Zhongfan
State Key Laboratory of Solid-State Lighting, Institute of Semiconductors, Chinese Academy of Sciences, Beijing, 100083, China.
Center for Nanochemistry (CNC), Beijing Science and Engineering Center for Nanocarbons, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
Adv Mater. 2019 Jun;31(23):e1807345. doi: 10.1002/adma.201807345. Epub 2019 Apr 16.
The growth of single-crystal III-nitride films with a low stress and dislocation density is crucial for the semiconductor industry. In particular, AlN-derived deep-ultraviolet light-emitting diodes (DUV-LEDs) have important applications in microelectronic technologies and environmental sciences but are still limited by large lattice and thermal mismatches between the epilayer and substrate. Here, the quasi-van der Waals epitaxial (QvdWE) growth of high-quality AlN films on graphene/sapphire substrates is reported and their application in high-performance DUV-LEDs is demonstrated. Guided by density functional theory calculations, it is found that pyrrolic nitrogen in graphene introduced by a plasma treatment greatly facilitates the AlN nucleation and enables fast growth of a mirror-smooth single-crystal film in a very short time of ≈0.5 h (≈50% decrease compared with the conventional process), thus leading to a largely reduced cost. Additionally, graphene effectively releases the biaxial stress (0.11 GPa) and reduces the dislocation density in the epilayer. The as-fabricated DUV-LED shows a low turn-on voltage, good reliability, and high output power. This study may provide a revolutionary technology for the epitaxial growth of AlN films and provide opportunities for scalable applications of graphene films.
生长具有低应力和低位错密度的单晶III族氮化物薄膜对半导体工业至关重要。特别是，基于AlN的深紫外发光二极管（DUV-LED）在微电子技术和环境科学中具有重要应用，但仍受外延层与衬底之间较大的晶格和热失配限制。在此，报道了在石墨烯/蓝宝石衬底上高质量AlN薄膜的准范德华外延（QvdWE）生长，并展示了其在高性能DUV-LED中的应用。在密度泛函理论计算的指导下，发现经等离子体处理引入石墨烯中的吡咯氮极大地促进了AlN成核，并能在约0.5 h的极短时间内实现镜面光滑单晶薄膜的快速生长（与传统工艺相比减少约50%），从而大幅降低成本。此外，石墨烯有效释放双轴应力（0.11 GPa）并降低外延层中的位错密度。所制备的DUV-LED显示出低开启电压、良好的可靠性和高输出功率。本研究可能为AlN薄膜的外延生长提供一项革命性技术，并为石墨烯薄膜的可扩展应用提供机会。
