Light-Programmable Reorientation of the Crystallographic <i>c</i> Axis of Tellurium Thin Films.

Abstract

Tellurium (Te), a two-dimensional material with pronounced structural anisotropy, exhibits exceptional electrical and optical properties that are highly sensitive to its crystallographic orientation. However, conventional syntheses offer limited control over the in-plane alignment of Te's crystallographic <i>c</i> axis, hindering large-scale integration. Here, we report a fundamentally different strategy to manipulate the <i>c</i>-axis orientation of Te thin films using linearly polarized picosecond laser pulses. We show that the <i>c</i> axis can be omnidirectionally reoriented perpendicular to the laser polarization, even in initially polycrystalline films. The reorientation is reversible, allowing for rewritable and spatially selective control of the <i>c</i>-axis orientation postdeposition. This light-driven approach opens a pathway for reconfigurable optoelectronic and photonic devices, such as active metasurfaces and CMOS-compatible architectures.