Piezoelectricity in two-dimensional (2D) transition metal dichalcogenides (TMDs) has attracted significant attention due to their unique crystal structure and the lack of inversion centers when the bulk TMDs thin down to monolayer. Although the piezoelectricity effect in atomic-thickness TMDs has been demonstrated, they are not scalable. Herein, we demonstrate a piezoelectric effect from large-scale, sputtered MoS2 and WS2 using a robust defect-engineering based on the thermal-solvent annealing and solvent immersion process. This yields a higher piezoelectric output over 20 times after annealing or solvent immersion. Indeed, the piezoelectric responses are strengthened with the increases of defect density. Moreover, the MoS2 or WS2 piezoelectric device array shows an exceptional piezoelectric sensitivity with a high-level uniformity and excellent environmental stability under ambient conditions. A detailed study of the sulfur vacancy-dependent property and its resultant asymmetric structure-induced piezoelectricity is reported. The proposed approach is scalable and can produce advanced materials for flexible piezoelectric devices to be used in emerging bioinspired robotics and biomedical applications.
| Identifer | oai:union.ndltd.org:unt.edu/info:ark/67531/metadc1808451 |
| Date | 05 1900 |
| Creators | Kim, Junyoung |
| Contributors | Choi, Wonbong, 1963-, Aouadi, Samir, Mehta, Gayatri |
| Publisher | University of North Texas |
| Source Sets | University of North Texas |
| Language | English |
| Detected Language | English |
| Type | Thesis or Dissertation |
| Format | ix, 52 pages : illustrations (chiefly color), Text |
| Rights | Public, Kim, Junyoung, Copyright, Copyright is held by the author, unless otherwise noted. All rights Reserved. |
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