Layered materials that do not form
a covalent bond in a vertical
direction can be prepared in a few atoms to one atom thickness without
dangling bonds. This distinctive characteristic of limiting thickness
around the sub-nanometer level allowed scientists to explore various
physical phenomena in the quantum realm. In addition to the contribution
to fundamental science, various applications were proposed. Representatively,
they were suggested as a promising material for future electronics.
This is because (i) the dangling-bond-free nature inhibits surface
scattering, thus carrier mobility can be maintained at sub-nanometer
range; (ii) the ultrathin nature allows the short-channel effect to
be overcome. In order to establish fundamental discoveries and utilize
them in practical applications, appropriate preparation methods are
required. On the other hand, adjusting properties to fit the desired
application properly is another critical issue. Hence, in this review,
we first describe the preparation method of layered materials. Proper
growth techniques for target applications and the growth of emerging
materials at the beginning stage will be extensively discussed. In
addition, we suggest interlayer engineering via intercalation
as a method for the development of artificial crystal. Since infinite
combinations of the host–intercalant combination are possible,
it is expected to expand the material system from the current compound
system. Finally, inevitable factors that layered materials must face
to be used as electronic applications will be introduced with possible
solutions. Emerging electronic devices realized by layered materials
are also discussed.
Protein cages, such
as viruses, are well-defined biological nanostructures
which are highly symmetrical and monodisperse. They are found in various
shapes and sizes and can encapsulate or template non-native materials.
Furthermore, the proteins can be chemically or genetically modified
giving them new properties. For these reasons, these protein structures
have received increasing attention in the field of polymer–protein
hybrid materials over the past years, however, advances are still
to be made. This Viewpoint highlights the different ways polymers
and protein cages or their subunits have been combined to understand
self-assembly and create functional materials.
We present the modification of the outer protein shell of cowpea chlorotic mottle virus (CCMV) with linear and strained alkyne groups. These functionalized protein capsids constitute valuable platforms for post-functionalization via click chemistry. After modification, the integrity of the capsid and the reversible disassembly behavior are preserved.
Summary
Two-dimensional (2D) organic-inorganic halide perovskites (OIHPs) with an alternating stacked structure of an organic layer and an inorganic layer draw significant attention for photovoltaics, multiple quantum-well, and passivation of three-dimensional perovskites. Although the low-cost and simple spin-coating process of these materials offers a vast platform to study fundamental properties and help them achieve rapid progress in electronics and optoelectronics, chemical vapor deposition (CVD) growth is also necessary for large-area, epitaxial, selective, and conformal growth. Here, one-step CVD strategies for 2D OIHP growth are proposed, and the growth trends depending on the precursor and substrate conditions are discussed. We report a CVD-grown nontoxic, lead-free 2D tin-OIHP flake to show the system offering a universal route to synthesize perovskite crystals based on arbitrary organic and inorganic components.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.