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NATURE MATERIALS | VOL 17 | MARCH 2018 | 210–220 | www.nature.com/naturematerials
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modelling results is an open issue for the
DFT community and deserves further
The result achieved by Iversen and
co-workers echoes several recent theoretical
works that revealed the presence of covalent-
like interlayer interactions in TMDs. For
instance, theoretical calculations found
appreciable charge accumulation around
the central plane between the S atom layers
of two adjacent PtS
, as illustrated in
Fig. 2. In this case, the vdW attractions are
so strong that they push the originally non-
bonding orbitals to overlap and form
a covalent-like quasi-bonding, thus
explaining the experimental observations
of layer-dependent bandgap modulation and
optical absorption, among the other physical
properties. The overlap of orbitals of
S atoms from two adjacent layers could
also be achieved by applying normal-
plane pressure, as recently demonstrated
by a high-pressure experiment that induced
the overlap of valence band states in
, giving rise to charge sharing
in the interlayer region and splitting of
the valence band maximum
. Now, the
solid experimental proof for the charge
accumulation in 1T-TiS
presented by Iversen and co-workers
not only enlightens the remarkable
interlayer interactions in TMDs, but may
also promote an emerging field, namely
where interlayer coupling is used as a
degree of freedom for manipulating the
electronic structures and thus tailoring
the electric, optical, thermoelectric and
magnetic properties of vdW homo-
and heterostructures. ❐
* and Wei Ji
National Center for Nanoscience and Technology,
Department of Physics,
Renmin University of China, Beijing, China.
*e-mail: email@example.com; firstname.lastname@example.org
Published online: 12 February 2018
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MATERIALS RESEARCH IN AFRICA
A thirst for advancement
The resource-rich continent of Africa is showing signs of signiﬁcant progress in materials science research and is
harnessing a plethora of human and material resources to tackle a wide range of challenges.
t the 9th International Conference
of the African Materials Research
Society (AMRS), which was held in
Gaborone, Botswana, on 11–14 December
2017, the diversity of international speakers
and increased number of African attendees
was a clear indication that the advancement
in materials science research in the
continent is gaining focus and momentum.
It is well known that the continent of
Africa is rich in natural resources such as oil,
minerals and agricultural land. However, it
is becoming more and more apparent that
Africa has an additional resource that is on
the rise. Its population is the most youthful on
Earth (with half being under the age of 25),
and is growing faster than anywhere else
— projected to grow from 1.2 billion to
over 3.5 billion by the end of this century
The growth of revenue from the resources
as well as a rich entrepreneurial energy
also making significant contributions to the
development of the continent. Although
the infrastructure for science education and
research is still lacking in many regions,
the combination of rich natural resources,
young population and entrepreneurial spirit
is ripe to foster new economic opportunities
and offer sustainable solutions to tackle
Africa’s pressing issues.
The themes of the 9th AMRS
conference (Fig. 1) were diverse; they
covered all aspects of the challenges that
Africa is facing today, including health,
water purification, agriculture, the
environment, energy, mining, construction,
nanotechnology, networking, computing
and materials science education.
The conference was led by plenary lectures
from a group of distinguished international
materials scientists, including Nobel
Laureate Jean-Marie Lehn (University of
Strasbourg), Tobin Marks and Sossina
Haile (both of Northwestern University),
Fig. 1 | The Okavango Delta in the north of Botswana is a popular tourist destination in the country.
The 9th International Conference of the AMRS was held in the capital city, Gaborone. Credit: image by