Enhanced piezoelectric effect at the edges of stepped molybdenum disulfide nanosheets

Song, X. et al. (2017) Enhanced piezoelectric effect at the edges of stepped molybdenum disulfide nanosheets. Nanoscale, 9(19), pp. 6189-6608. (doi: 10.1039/c6nr09275f) (PMID:28338700)

Abstract

The development of piezoelectric layered materials may be one of the key elements enabling expansion of nanotechnology, as they offer a solution for the construction of efficient transducers for a wide range of applications, including self-powered devices. Here, we investigate the piezoelectric effect in multilayer (ML) stepped MoS2 flakes obtained by liquid-phase exfoliation, which is especially interesting because it may allow the scalable fabrication of electronic devices using large area deposition techniques (e.g. solution casting, spray coating, inkjet printing). By using a conductive atomic force microscope we map the piezoelectricity of the MoS2 flakes at the nanoscale. Our experiments demonstrate the presence of electrical current densities above 100 A cm−2 when the flakes are strained in the absence of bias, and the current increases proportional to the bias. Simultaneously collected topographic and current maps demonstrate that the edges of stepped ML MoS2 flakes promote the piezoelectric effect, where the largest currents are observed. Density functional theory calculations are consistent with the ring-like piezoelectric potential generated when the flakes are strained, as well as the enhanced piezoelectric effect at edges. Our results pave the way to the design of piezoelectric devices using layered materials.

• Item Type: Articles
• Additional Information: We acknowledge funding from the Young 1000 Global Talent Recruitment Program of the Ministry of Education of China (KG and ML), the National Natural Science Foundation of China (grants no. 61502326, 41550110223, 11661131002, 11375127), the Jiangsu Government (grant no. BK20150343, BK20130280), the Ministry of Finance of China (grant no. SX21400213), the Young 973 National Program of the Chinese Ministry of Science and Technology (grant no. 2015CB932700) and the ERC Grant Hetero2D, the EU Graphene Flagship, EPSRC Grants EP/K01711X/1, EP/K017144/1, EP/L016087/1, EP/N010345/1, the Collaborative Innovation Center of Suzhou Nano Science & Technology, the Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices and the Priority Academic Program Development of Jiangsu Higher Education Institutions.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Grustan Gutierrez, Dr Enric
• Authors: Song, X., Hui, F., Gilmore, K., Wang, B., Jing, G., Fan, Z., Grustan Gutierrez, E., Shi, Y., Lombardi, L., Hodge, S. A., Ferrarie, A. C., and Lanza, M.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: Nanoscale
• Publisher: Royal Society of Chemistry
• ISSN: 2040-3364
• ISSN (Online): 2040-3372
• Published Online: 23 February 2017