Graphene-assisted spontaneous relaxation towards dislocation-free heteroepitaxy

Autor: Beom Seok Kang, Chanyeol Choi, Sungkyu Kim, Peng Chen, Yifan Nie, David A. Muller, Yongmin Baek, Hyunseok Kim, Kyusang Lee, Jaeyong Lee, Minho Joo, Sang-Hoon Bae, Kuangye Lu, Chansoo Kim, Jaewoo Shim, Jinhee Park, Yimo Han, Wei Kong, Hyun Kum, Jeehwan Kim, Kuan Qiao
Rok vydání: 2020
Předmět:
Zdroj: Nature Nanotechnology. 15:272-276
ISSN: 1748-3395
1748-3387
DOI: 10.1038/s41565-020-0633-5
Popis: Although conventional homoepitaxy forms high-quality epitaxial layers1-5, the limited set of material systems for commercially available wafers restricts the range of materials that can be grown homoepitaxially. At the same time, conventional heteroepitaxy of lattice-mismatched systems produces dislocations above a critical strain energy to release the accumulated strain energy as the film thickness increases. The formation of dislocations, which severely degrade electronic/photonic device performances6-8, is fundamentally unavoidable in highly lattice-mismatched epitaxy9-11. Here, we introduce a unique mechanism of relaxing misfit strain in heteroepitaxial films that can enable effective lattice engineering. We have observed that heteroepitaxy on graphene-coated substrates allows for spontaneous relaxation of misfit strain owing to the slippery graphene surface while achieving single-crystalline films by reading the atomic potential from the substrate. This spontaneous relaxation technique could transform the monolithic integration of largely lattice-mismatched systems by covering a wide range of the misfit spectrum to enhance and broaden the functionality of semiconductor devices for advanced electronics and photonics.
Databáze: OpenAIRE