石墨烯上异质远程外延GaN的研究

Mechanism of Remote Heteroepitaxial GaN Growth on Graphene

远程外延是一种用于生产单晶、独立式薄膜和结构的新兴技术,该方法使用二维范德瓦耳斯材料作为半透明夹层,实现外延生长及外延层在二维层界面的剥离。本文研究了在蓝宝石衬底上利用单层石墨烯作中间层异质远程外延GaN成核层、GaN薄膜。结果表明,GaN成核岛具有良好的取向,通过参数调整,可实现致密的GaN成核层。AFM和XRD测试结果证实,与同样条件下蓝宝石衬底上直接生长的GaN薄膜相比,石墨烯上异质远程外延得到的GaN薄膜具有更低的表面粗糙度和位错密度。

Remote epitaxy is an emerging technology for producing single-crystalline,free-standing thin films and structures.The method uses 2D van der Waals materials as semi-transparent interlayers that enable epitaxy and release of epitaxial layers at the 2D layer interface.The use of single-layer graphene as the interlayer for heterogeneous remote epitaxial GaN nucleation layer and GaN film on the sapphire substrate was studied.The result shows that GaN nucleation island has a good orientation.Through parameter adjustment,a dense GaN nucleation layer was obtained.AFM observation and XRD detection confirm that GaN thin film has lower surface roughness and dislocation density compared with film that grow directly on sapphire substrate under the same conditions.The existence of graphene after growing GaN film was confirmed by Raman spectra.