singleatomthick

Singleatomthick is a descriptive term used to characterize materials or films that consist of only a single layer of atoms. In practice it refers to two-dimensional 2D materials whose thickness corresponds to a single atomic layer, typically on the order of a fraction of a nanometer. Graphene is the prototypical example, effectively a single-atom-thick sheet of carbon arranged in a hexagonal lattice. For graphene, reported thickness is often taken as the interlayer spacing in graphite, about 0.335 nanometers, though some models treat single-layer graphene as having negligible thickness and focus on the properties of the 2D plane itself.

Other materials can form single-atom-thick layers, including transition metal dichalcogenides such as MoS2 and WS2; hexagonal boron nitride; phosphorene; and silicene. These materials share the characteristic of high in-plane strength and tunable electronic, optical, and chemical properties. Graphene offers exceptional electrical conductivity and mechanical stiffness but lacks an intrinsic band gap; many 2D semiconductors exhibit sizable band gaps, enabling transistor action in ultrathin form.

Fabrication methods include mechanical exfoliation, chemical vapor deposition, and epitaxial growth. Characterization techniques include atomic force microscopy, transmission electron microscopy, and Raman spectroscopy, which can verify thickness and assess quality and defects.

Potential applications span flexible and transparent electronics, sensors, energy storage and catalysis, and composite materials. Challenges for commercialization of single-atom-thick films include defect control, environmental stability, large-area uniformity, and integration with existing manufacturing processes.

Because singleatomthick is a descriptive term rather than a precise physical quantity, exact thickness can vary among materials and measurement conventions; nonetheless, the concept captures the extreme thinness and unique physics of 2D materials.