Improved Epitaxy of AlN Film for Deep-Ultraviolet Light-Emitting Diodes Enabled by Graphene.
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.
['Chen|Zhaolong|Z|', 'Liu|Zhiqiang|Z|', 'Wei|Tongbo|T|', 'Yang|Shenyuan|S|', 'Dou|Zhipeng|Z|', 'Wang|Yunyu|Y|', 'Ci|Haina|H|', 'Chang|Hongliang|H|', 'Qi|Yue|Y|', 'Yan|Jianchang|J|', 'Wang|Junxi|J|', 'Zhang|Yanfeng|Y|', 'Gao|Peng|P|', 'Li|Jinmin|J|', 'Liu|Zhongfan|Z|https://orcid.org/0000-0001-5554-1902']
deep-ultraviolet light-emitting diodes graphene quasi-van der Waals epitaxy aluminum nitride chemical vapor deposition