Piezotronics modulates high sensitivity relative humidity sensor based on single tellurium microwire

Micro/nano scale architectures found in nature have unique functionalities, and their discovery has led to significant advancements in various fields of natural and engineering sciences, such as electronics, machinery, materials and energy. The piezoelectric micro/nano semiconductors, comprised of unique hierarchical structures and strain induced charges, are representative examples which inspired the development of various mechanics, electrical and environmental coupling systems, owing to their high sensitivity and fast responsivity to mechanical and humidity. In this paper, we use a hydrothermal method to synthesize Tellurium (Te) microwires, and fabricate a high sensitive humidity sensor based on single Te microwire through piezoelectric modulation. When applying stress to the Te microwire, the output current of the humidity sensor dramatically increased, experimental results and theoretical simulations indicated that the piezotronic effect could effectively tune the Schottky barrier height (SBH), thus enhancing the sensitivity of humidity sensor. The optimized sensitivity reaches to 1.6 × 10⁵% through applied external strain at low humidity. This result demonstrates that with piezoelectric modulation, Te microwire can be serve as an effective semiconductor gas sensor. (paper)