Ida Marie Høiaas(1), Dong-Chul Kim(1,2) and Helge Weman(1,2) (1) Department of Electronics and Telecommunications, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway (2) CrayoNano AS, Otto Nielsens vei 12, NO-7052 Trondheim, Norway  An interesting area of graphene research is the combination of graphene and Si into new hybrid materials and devices. Several examples[1,2] of combinations exist that exploit heterostructures of Si and graphene, but these examples mostly combine transferred graphene on top of conventionally grown crystalline Si.We here report a heterostructure comprised of graphene and a thin film of polycrystalline Si (poly-Si). The Si is deposited by Al-induced crystallization (AIC) of amorphous Si (a-Si) on top of graphene, resulting in [111]-oriented Si under the process conditions employed. It was found that the AIC of Si on graphene is of higher quality compared to that on a SiO2/Si(100) substrate and could easily be exfoliated from the SiO2/Si(100) substrate, making it possible to study the Raman spectra of both materials in the same area through the transparent graphene. Raman measurements show that the graphene is intact after the AIC process, retaining its characteristic phonon spectrum without any appearance of the D peak. In addition, a red shift of Raman peaks is observed for graphene (which is more pronounced for the 2D peak) and poly-Si. A correlation between the red shifts of the Raman peaks of Si and graphene indicates an epitaxial relationship between the poly-Si and graphene[3]. [1] X. Wang, et al., Nature Photonics, 7 (2013) 888-891. [2] F. Vaianella, et al., Journal of Applied Physics, 117 (2015) 243102. [3] I. M. Høiaas, D.-C. Kim, and H. Weman, Applied Physics Letters, 108 (2016) 161906.  Ida Marie Høiaas is currently a PhD student at the Norwegian University of Technology and Science (NTNU), at the Department of Electronics and Telecommunications. Her research is mainly focused at developing optoelectronic devices combining 1D- and 2D-materials. She received her MSc. degree in Nanotechnology from NTNU in 2014. |
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