Production of Tellurene Nanoribbons.

The controllable synthesis of one-dimensional (1D) nanostructures is foundational to nanotechnology but often relies on metal catalysts, introducing impurities and process incompatibility. Here, we demonstrate a catalyst-free and broadly applicable strategy for the direct production of tellurene nanoribbons (TeNRs) via molecular beam epitaxy. The approach works on a wide range of exfoliated two‑dimensional (2D) materials and even on non‑layered substrates, although the degree of alignment and ribbon density are substrate dependent. Our approach leverages two synergistic growth paradigms. First, we employ van der Waals epitaxy on various exfoliated 2D materials, achieving in-plane TeNRs. Second, we harness an edge-attachment mechanism, where active step edges serve as anchoring points to initiate and direct the growth of freestanding TeNRs. Theoretical calculations reveal that this anisotropic growth is kinetically driven by a stark contrast between the stability of prismatic sidewalls and the dynamic reconstruction of the (0 0 0 1) growth front of Te. This approach provides precise kinetic control over morphology through substrate temperature and flux, yielding β-phase TeNRs. Our work establishes an effective pathway for synthesizing elemental 1D nanostructures without catalysts, bridging the gap between surface-guided and freestanding growth paradigms, with direct implications for integrating pure tellurium nanostructures into advanced electronics and optoelectronics.