1 research outputs found
Facet Engineering by Sculpting Artificial Edges on 2D Black Phosphorus for Localized and Selective Piezoelectric Response
The ability to achieve orientation selectivity in piezoelectric
response and thereby identifying its active piezoelectric facets with
superior response is imperative for the breakthrough in piezoelectricity;
still, it remains a challenge due to the presence of the mixed facets
in contemporary semicrystalline piezoelectric materials. Accurate
determination of in-plane and out-of-plane piezoelectric coefficients
in these materials is practically impossible due to the involvement
of components of other piezoelectric tensors arising from the randomly
oriented molecules. This report delves into the exploration of the
piezoelectric and ferroelectric response at piezoelectric facets such
as basal plane and edges of two-dimensional (2D) black phosphorus
(BP) flake and thereby measures the in-plane and out-of-plane piezoelectric
coefficients in their pure form. In this report, the localized piezoelectric
facets (artificial edges) are meticulously sculpted using a low-power
focused laser, resulting in precise piezoelectric response selectivity
at facets of the BP flake. The experimental findings, supported by
theoretical calculations, demonstrate that the in-plane piezoelectric
response is prominent at the edges, while the out-of-plane response
is significant at the basal plane of the flakes. Moreover, thinner
flakes exhibit lower coercive voltage (VC) and voltage at the spontaneous polarization (VS), indicating a stronger ferroelectric response as compared
to thicker flakes. The experimental results offer an innovative path
for deciphering the active piezoelectric coefficient along different
crystal facets of 2D materials, offering exciting prospects for further
research beyond the confinement of contemporary piezoelectric materials