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Visualizing Piezoelectricity on 2D Crystals Nanobubbles
Author(s) -
Wang Wei,
Zhou Lijun,
Hu Sheng,
Novoselov Konstantin S.,
Cao Yang
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202005053
Subject(s) - piezoelectricity , materials science , kelvin probe force microscope , piezoelectric coefficient , piezoresponse force microscopy , nanotechnology , condensed matter physics , optoelectronics , dielectric , atomic force microscopy , ferroelectricity , composite material , physics
Abstract 2D crystals with noncentrosymmetric structures exhibit piezoelectric properties that show great potential for applications in energy conversion and electromechanical devices. Quantitative visualization of piezoelectric field spatial distribution is expected to offer a better understanding of macroscopic piezoelectricity, yet remains to be realized. Here, a technique of mapping piezoelectric potential on 2D materials bubbles based on the measurements of surface potential using kelvin probe force microscope is reported. By using odd number of layers hexagonal boron nitride and MoS 2 nanobubbles, strain‐induced piezoelectric potential profiles are quantitatively visualized on the bubbles. The obtained piezoelectric coefficient is 3.4 ± 1.2 × 10 −10 C m −1 and 3.3 ± 0.2 × 10 −10 C m −1 for hBN and MoS 2 , in agreement with the values reported. On the contrary, homogeneous distribution of surface potential is measured on even number of layers crystals bubbles where the crystal's inversion symmetry is restored. Using such technique, in situ visualization of photogenerated charge carrier separation under piezoelectric potential is also achieved, which offers a platform of investigating the coupling between piezoelectricity and photoelectric effect, and an approach of tuning piezoelectric field. The present work should aid the understanding of local piezoelectric potential and its various affecting factors including substrate doping and external stimuli, and give insights for designing piezoelectric nanodevices based on 2D nanobubbles.