One-Dimensional Atomic Tellurium Chains in Boron Nitride Nanotubes: Synthesis and Devices

Tellurium has a unique one-dimensional (1D) helical chain crystal structure. The adjacent tellurium atoms in a single chain are covalently bonded, and different chains interact with each other by van der Waals force to form planar and bulk crystal. As a narrow-bandgap p-type semiconductor, bulk tellurium has a direct bandgap of ~0.35 eV. Here, 1D atomic tellurium chains were grown inside the boron nitride nanotubes (BNNTs) whose inner diameter was only a few nanometers. 1D tellurium crystal was synthesized and grew along the direction of BNNTs due to the natural confinement of the BNNT physical structure. Raman spectroscopy and energy-dispersive X-ray spectroscopy (EDX) were utilized to characterize the tellurium crystal structure and guaranteed the high quality of the Te-BNNT samples. The electrical properties of Te-BNNT devices were studied by current-voltage measurement. The devices were fabricated by transferring Te-BNNTs onto SiO₂/p⁺⁺ Si substrate, Ar-SF₆ dry etching, and deposition of metal electrodes on top of the nanotubes. The realization of BNNTs-capsulated tellurium chains enhanced the current capacity of tellurium crystal several times compared to bare tellurium nanowires.