Wei Kong（1）, Wenhao Li（1）, Xuechun Sun（1）, Kuan Qiao（1）, Yunpeng Liu（2）, Jeehwan Kim（2）

（1） Department of Material Science and Engineering, Westlake University, Hangzhou, Zhejiang, China 310024

（2）Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA 02139

 

III-nitride materials including GaN and their ternary alloys have been the key materials to realize advanced electronic and optoelectronic devices. However, the epitaxy of III-nitrides is severely limited by substrates. We have previously shown the synthesis of GaAs on two dimensional materials followed by the separation of GaAs epitaxial thin film from its substrate [1], by utilizing the process so-called “remote-epitaxy”. Such discovery reveals the possibilities towards the fabrication of defect-free III-nitrides without the limitations posed by substrates.

     We previously demonstrated remote-epitaxy of GaN based on transferred graphene, but we faces challenges on yield and substrate reusability [2]. Recently, we demonstrated a novel platform for GaN remote-epitaxy by utilizing the quasi-two-dimensional graphene buffer layer (GBL) of graphitized SiC. After mechanically removing epitaxial graphene on a graphitized SiC wafer, the quasi-two-dimensional graphene buffer layer (GBL) surface remains intact for epitaxial growth. The reduced vdW gap between the epilayer and substrate enhances epitaxial interaction, promoting remote epitaxy. Significantly improved nucleation and convergent quality of GaN are achieved on GBL, resulting in the high quality GaN grown on two-dimensional materials. The GBL surface exhibits excellent resistance to harsh growth environments, allowing remote epitaxy in even oxygen environment, such as for ZnO.

​

[1] Kim, Yunjo, et al. "Remote epitaxy through graphene enables two-dimensional material-based layer transfer." Nature 544.7650 (2017): 340.

[2] Kong, et al. "Polarity governs atomic interaction through two-dimensional materials." Nature materials 17.11 (2018): 999.

[3] Qiao, et al. "Graphene Buffer Layer on SiC as a Release Layer for High-Quality

Freestanding Semiconductor Membranes" Nano Lett. 21 4013 (2021)