Ultrafast laser shock straining in chiral chain 2D materials: Mold topology‑controlled anisotropic deformation

As 2D materials race toward flexible electronics, precisely tailoring their strain fields without cracking crystals remains a grand challenge. Now, a Purdue team led by Prof. Gary J. Cheng and Prof. Wenzhuo Wu demonstrates the first laser-shock imprinting (LSI) on chiral-chain tellurene, revealing orientation-dependent deformation that retains single-crystal integrity while generating dense dislocation networks—offering a universal route for nanoscale strain engineering of anisotropic 2D systems.

Why LSI on Tellurene Matters

• Ultrafast & High-Resolution: 5-ns, 0.4 GW cm^-2 pulse delivers smooth 3-D nanoshaping with sub-micron feature control.
• Orientation-Sensitive Mechanics: Parallel strain drives chain gliding/rotation; transverse strain triggers multimodal shear—tuning bandgap and carrier mobility on demand.
• Single-Crystal Retention: Severe plastic zones coexist with pristine lattice, enabling functional device integration without loss of crystallinity.

Innovative Design & Features

• Mold-Topology Control: Sharp-edged gratings produce localized shear > homogeneous CD-mold fields, forming dislocation tangles and 6.37° lattice rotations.
• Dual Deformation Regimes: MD-validated models show chain sliding (‖) versus chain twisting (⊥) at 460 MPa shear stress—matching HR-TEM observations.
• Raman Fingerprint: Perpendicular strain red-shifts A₁ mode to 117 cm^-1 (tensile); parallel strain blue-shifts to 121.5 cm^-1 (compressive), providing non-destructive strain read-out.

Applications & Outlook

• Strain-Tunable Photodetectors: Anisotropic absorption edges promise CMOS-compatible, bendable IR sensors.
• Flexible Thermoelectrics: Controlled defect networks scatter phonons while preserving σ, boosting ZT in wearable energy harvesters.
• Scalable Manufacturing: Roll-to-roll LSI molds compatible with 4-inch wafers; team targets cm² tellurene TEG arrays delivering >1 mW cm^-2.

This work establishes LSI as a precision tool for sculpting 2D chiral semiconductors, bridging ultrafast mechanics with optoelectronic property design. Stay tuned for more advances from Prof. Cheng & Prof. Wu’s labs!