Fascinating Electrical Transport Behavior of Topological Insulator Bi₂Te₃ Nanorods: Toward Electrically Responsive Smart Materials

Electrical conductivity and dielectric parameters are general inherent features of materials. Controlling these characteristics through applied bias will add a new dimension to regulate the dynamic response of smart materials. Here, a fascinating electrical transport behavior is observed in topological insulator (TI) Bi₂Te₃ nanorods, which will play a vital role in intelligent materials or devices as a unit for information reception, processing or feedback. The Bi₂Te₃ nanorod aggregates exhibit a monotonic resistance response to voltage, with observed four-fold change of electrical conductivity in a small range electric field of 1 V mm⁻¹. The dielectric constant and dielectric loss of Bi₂Te₃ nanorod composites also show strong dependences on bias voltage due to the unique electrical transport characteristics. The unique voltage-controlled electrical responses are attributed to the change of Fermi levels within the band structure of disordered TI nanorods, which are non-parallel to the applied electric field. The excellent controllable inherent characteristics through electric field endows Bi₂Te₃ nanomaterials bright prospects for applications in smart devices and resistive random access memories.