Strain engineering on the electronic states of two-dimensional GaN/graphene heterostructure

Abstract

Combining two different layered structures to form a van der Waals (vdW) heterostructure has recently emerged as an intriguing way of designing electronic and optoelectronic devices.

Tunable Electronic Properties of Graphene/g-AlN Heterostructure: The Effect of Vacancy and Strain Engineering

“….80, and 3.27 eV, respectively, and the work function of graphene agrees with that in Ref. [18]. The differences in WF between graphene and g-AlN, g-AlN-V Al , and g-AlN-V N are −0.84, −1.18, and 0.97 eV, respectively, once again proving that graphene would lose electrons (donor) in Gr/g-AlN and Gr/g-AlN-V Al , while obtaining electrons (acceptor) in Gr/g-AlN-V N .…”

“…The results in Figure 1a,b and Figure 3a prove little variation of the band structures of g-AlN and graphene before and after contacting, both with nonmagnetic nature. The results are similar to that of Gr/g-GaN [18,19], Gr/Sb [41], and Gr/MoSe2 heterojunctions [42]. The Fermi level exactly passes through the Dirac cone, which indicates that the charge transfer between graphene and g-AlN sublayers are negligible and barely affects the nature of graphene.…”

“…Additionally, the magnetic nature in freestanding g-AlN-V N disappears after contacting graphene, which indicates that graphene could also tune the magnetism of g-AlN-V N , which shows potential application in electronic devices. The same phenomenon is also found by comparing the band structures of GaN-V N in [45] and Gr/g-GaN-V N in [18]. The disappearance of magnetism in Gr/g-AlN-V N is because electrons occupied on the vacancy induced defect states would transfer to graphene, which leads the defect levels to shift up to conduction bands and then become unoccupied.…”

“…The Fermi level exactly passes through the Dirac cone, which indicates that the charge transfer between graphene and g-AlN sublayers are negligible and barely affects the nature of graphene. Based on Equation 2 to that of Gr/g-GaN [18,19], Gr/Sb [41], and Gr/MoSe 2 heterojunctions [42]. The Fermi level exactly passes through the Dirac cone, which indicates that the charge transfer between graphene and g-AlN sublayers are negligible and barely affects the nature of graphene.…”

“…Heterostructure, by constructing graphene with other 2D materials, is an effective method to broaden the application of graphene. Recently, many works have been reported, such as electrostatically created bipolar graphene heterojunction [16], graphene/MoS 2 [17], as well as graphene/g-GaN [18,19]. Besides, Ahmad et al used a modified Hummer's method to obtain a photoconducting material based on the boron nitride-graphene oxide composite layer.…”