Fast Twist Angle Mapping of Bilayer Graphene Using Spectroscopic Ellipsometric Contrast Microscopy

• DOI: 10.1021/acs.nanolett.3c00619
• Publication Date: 2023-06-08T17:15:37Z
• Authors: Teja Potočnik; Oliver Burton; Marcel Reutzel; David Schmitt; Jan Philipp Bange; Stefan Mathias; Fabian R. Geisenhof; R. Thomas Weitz; Linyuan Xin; Hannah J. Joyce; Stephan Hofmann; Jack A. Alexander...
• Keywords: Bilayer graphene; Characterization

Twisted bilayer graphene provides an ideal solid-state model to explore correlated material properties and opportunities for a variety of optoelectronic applications, but reliable, fast characterization the twist angle remains challenge. Here we introduce spectroscopic ellipsometric contrast microscopy (SECM) as tool mapping disorder in optically resonant twisted graphene. We optimize angles enhance image based on measured calculated reflection coefficients incident light. The optical resonances associated with van Hove singularities correlate well Raman angle-resolved photoelectron emission spectroscopy, confirming accuracy SECM. results highlight advantages SECM, which proves be fast, nondestructive method over large areas, unlocking process, material, device screening cross-correlative measurement potential multilayer materials.