Enhanced piezoelectric effect at the edges of stepped molybdenum disulfide nanosheets.
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 MoS2flakes 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 MoS2flakes at the nanoscale. Our experiments demonstrate the presence of electrical current densities above 100 A cm-2when 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 MoS2flakes 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.
Institute of Functional Nano & Soft Materials (FUNSOM), Collaborative Innovation Center of Suzhou Nanoscience and Technology, Soochow University, 199 Ren-Ai Road, Suzhou, 215123, China. mlanza@suda.edu.cn.
Xiaoxue
X
Song
Fei
F
Hui
Keith
K
Gilmore
Bingru
B
Wang
Guangyin
G
Jing
Zhongchao
Z
Fan
Enric
E
Grustan-Gutierrez
Yuanyuan
Y
Shi
Lucia
L
Lombardi
Stephen A
SA
Hodge
Andrea C
AC
Ferrari
Mario
M
Lanza