石墨烯上外延生长氮化物（氮化镓和氮化铝）可以获得易转移、柔性的光电器件，成为近几年研究的热点，这种全新的外延方法被称为准范德瓦耳斯外延。然而，由于石墨烯表面缺乏悬挂键，限制了氮化物在其上成核。因此，其外延生长机理与传统异质外延存在较大差异，有待于深入研究。本项目拟采用氢化物气相外延法，在石墨烯上开展氮化物材料的外延生长研究。结合第一性原理计算，通过对石墨烯表面化学处理，促进氮化物成核，系统研究石墨烯上氮化物的成核及生长机理，建立准范德瓦耳斯外延的生长模型；此外，通过对界面生长模式的调控，进一步深入研究缺陷和应力控制技术，探索获得高质量、可转移的氮化物单晶材料的有效途径，为开发自支撑氮化物衬底材料奠定基础。

Recently, heteroepitaxy of nitride (GaN and AlN) on graphene gains great interest due to the various applications of flexible and transferable optoelectronic devices. It is a new approach known as quasi-van der Waals epitaxy. However, because of the lack of dangling bonds on the surface of graphene, the nucleation of nitride is limited. Therefore, the mechanism of this heteroepitaxy is different from the traditional heteroepitaxy and needs to make a further investigation. The proposed project will study on heteroepitaxy of nitride on graphene by hydride vapor phase epitaxy. Combined with first-principles calculation, by chemical treatment of the surface of graphene for promoting nucleation of nitride, we will study the mechanism of nucleation and growth of nitride on graphene systemically and establish the growth model of the quasi-van der Waals epitaxy. In addition, by regulation of the interface growth model, the project will also carry out an in-depth investigation of defects and strain control technology, explore an effective way to obtain a high quality and transferred nitride single crystal material for giving a great support for the development of free-standing nitride substrate.