jp9b06404_si_001.pdf (1.02 MB)
Vertical van der Waals Heterostructure of Single Layer InSe and SiGe
journal contribution
posted on 2019-12-15, 22:03 authored by I. Eren, S. Ozen, Y. Sozen, M. Yagmurcukardes, H. SahinWe present a first-principles investigation on the stability,
electronic
structure, and mechanical response of ultrathin heterostructures composed
of single layers of InSe and SiGe. First, by performing total energy
optimization and phonon calculations, we show that single layers of
InSe and SiGe can form dynamically stable heterostructures in 12 different
stacking types. Valence and conduction band edges of the heterobilayers
form a type-I heterojunction having a tiny band gap ranging between
0.09 and 0.48 eV. Calculations on elastic-stiffness tensor reveal
that two mechanically soft single layers form a heterostructure which
is stiffer than the constituent layers because of relatively strong
interlayer interaction. Moreover, phonon analysis shows that the bilayer
heterostructure has highly Raman active modes at 205.3 and 43.7 cm–1, stemming from the out-of-plane interlayer mode and
layer breathing mode, respectively. Our results show that, as a stable
type-I heterojunction, ultrathin heterobilayer of InSe/SiGe holds
promise for nanoscale device applications.