Synthetic Band Structure Engineering of Graphene Using Block Copolymer-Templated Dielectric Superlattices

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Engineering the electronic band structure of 2D materials using superlattice (SL) potentials is key for novel electronics.
• Remote SLs, created by nanopatterning nearby dielectrics, offer tunable electronic properties in 2D crystals.

Purpose of the Study:

• To demonstrate the use of block copolymer (BCP)-templated dielectric nanopatterns for fabricating remote SLs in 2D materials.
• To investigate the effectiveness of alumina (AlO) nanopatterns for creating tunable SL potentials in graphene.

Main Methods:

• Fabrication of hexagonal alumina nanopatterns with a 38 nm SL wavelength using BCP-templated vapor phase infiltration.
• Direct conversion of self-assembled BCP films into dielectric nanopatterns, avoiding etching steps.
• Electronic transport measurements of graphene under varying conditions to detect SL effects.

Main Results:

• Successful creation of remote SL potentials in graphene, evidenced by replica Dirac points and Hofstadter mini-gaps.
• Consistent lattice symmetry and periodicity achieved at a macroscopic scale despite inherent BCP rotational disorder.
• Demonstration of etch-free, high-grade metal oxide SL fabrication via BCP nanopatterning.

Conclusions:

• BCP-templated dielectric nanopatterns are effective for fabricating remote SLs in 2D materials.
• This scalable and cost-effective approach holds significant potential for advanced electronic device engineering.
• Optimized nanopattern fabrication ensures reliable SL potential formation for tunable electronic properties.