Related Experiment Video
Updated: Mar 17, 2026

Fabricating van der Waals Heterostructures with Precise Rotational Alignment
Published on: July 5, 2019
Precise Twist Angle Determination in Twisted WSe2 via Optical Moiré Phonons
Nicolai-Leonid Bathen1,2, Thorsten Deilmann3, Ana Senkić1
1Institute of Physics, University of Münster, 48149 Münster, Germany.
None:
Twisted bilayers of transition metal dichalcogenides (TMDC) form moiré superlattices hosting localized excitons and enabling access to Mott-Hubbard physics by the formation of moiré minibands. However, their electronic properties are highly sensitive to twist angle fluctuations, disorder, and lattice reconstructions, making fast and noninvasive local characterization challenging. Here, we correlate twist angle variations in twisted WSe2 bilayers across micrometer length scales using lateral force microscopy (LFM) and micro-Raman spectroscopy. We reveal twist angle variations exceeding 1° across optically and transport-relevant length scales. For twist angles in the range 3° < α < 12°, distinct Raman signatures from optical moiré phonons enable high-precision twist angle determination with sub-micrometer spatial resolution under ambient conditions. Our approach achieves a precision better than ± 0.3° particularly in the low-twist angle regime relevant for correlation physics and is applicable to hBN-encapsulated heterostructures, establishing micro-Raman spectroscopy as a rapid, noninvasive tool for twist angle screening.
Related Concept Videos
Angle of Twist - Elastic Range
Angle of Twist: Problem Solving
IR Spectrum Peak Splitting: Symmetric vs Asymmetric Vibrations
IR Spectroscopy: Hooke's Law Approximation of Molecular Vibration
According to Hooke's law, the vibrational frequency is directly proportional to...
Unsymmetric Bending - Angle of Neutral Axis
When a bending moment is applied at an angle θ concerning the vertical axis of a symmetrical member, it can be resolved into components along the member's principal...
NMR Spectroscopy: Spin–Spin Coupling

