Abstract
Since its discovery in 1991 and 2004, carbon nanotubes (CNTs) by Sumio Iijima, and graphene by Andre Geim and Konstantin Novoselov in 2004, these materials have been extensively studied around the world. Both materials have electronic, thermal, magnetic, optical, chemical, and mechanical extraordinary properties. International Technology Roadmap for Semiconductors (ITRS) has predicted that these nanomaterials are potential replacements of the conventional materials used in the manufacture of integrated circuits. Two of the technological aspects that both materials share and have reduced their extensive use are processing and dispersion required to homogenize the electrical properties of the materials based on them. Fortunately, these problems are being solved thanks to the ongoing investigation, and in a short time the materials used in today's electronics industry will be replaced by devices based on these novel materials. The impact of the applications of both materials in the electronics industry, as well as future trends in the following decades are discussed in this paper.
TopBackground
Carbon nanomaterials possess unique properties that can be exploited electrical, thermal, chemical and mechanically to provide applications in areas such as composite materials, energy storage and conversion, sensors, drug delivery, field emission devices, and nanoscale electronic components. Three different morphologies between carbon nanomaterials can be distinguished: carbon nanotubes, fullerenes and graphene. Carbon nanotubes and graphene have been used more extensively in the electronic industry. Next, a brief description of their properties is made with the purpose of knowing the advantages of these materials for electronic applications. The basic concepts of each type of material have been separated for a better description.
Carbon Nanotubes
A carbon nanotube can be defined as a set of cylinder-shaped graphite sheets. Carbon nanotubes (CNTs) can be categorized by the number of graphite layers in their structure: Single-Wall Nanotubes (SWNTs) containing a single layer (see Figure 1), Double-Wall Nanotubes (DWNTs) with two layers, and Multi-Wall Nanotubes (MWNTs) that contain more of two layers (see Figure 2). Two main physical properties are associated directly with electronic applications: high thermal and electrical conductivity (Vargas-Bernal, 2012). Carbon nanotubes and their compounds exhibit extraordinary electrical properties useful for electronic organic materials, and can be used for a wide range of new and existing applications such as conductive plastics, flat-panel displays either as flexible displays or touch screens, micro-and nano-electronics (transistors), radar-absorbing coating, ultra-capacitors, solar cells, batteries with improved lifetime, hydrogen storage cells, conductors, smart textiles, electrochemical sensors, biosensors, and gas sensors. A more detailed study of their properties in found in Vargas-Bernal, 2012.
Figure 1.
Structure of the single-wall carbon nanotube (SWNT)
Figure 2.
Structure of the multi-wall carbon nanotube (MWNT)
Key Terms in this Chapter
Electromagnetic Shielding: The action of reducing and/or isolating the electromagnetic field in a space by blocking the electromagnetic waves with barriers made of conductive and/or magnetic materials.
Current Density: The electric current per unit area of cross section, and as vectorial quantity it has magnitude, direction, and sense.
Carbon Nanotubes: Allotropes of carbon with a cylindrical nanostructure of length-to-diameter of up to 132,000,000:1, which have unusual properties and valuable for nanotechnology, electronics, optics and other fields of materials science and technology.
Graphene: A two-dimensional, crystalline allotrope of carbon whose atoms are densely packed in a regular sp 2 -bonded atomic-scale chicken wire (hexagonal) pattern composed by a one-atom thick layer of graphite.
Composites: Materials made from two or more constituents materials with significantly different physical and/or chemical properties, that when are combined, produce a material with different characteristics from the individual components.
Carbon Nanomaterials: Nanostructures of carbon such as fullerenes, carbon nanotubes, nanofibers and graphene with unique physicochemical properties with multiple technological applications.
Microelectronics: The study and manufacture (or microfabrication) of very small electronic designs and components normally in micrometer-scale o smaller by means of semiconductors.
Interconnect: A path of material that connects two elements or components in an IC, through which electrical current is transported.
Electrical Conductivity: The physical property that quantifies how strongly a given material opposes the flow of electrical current. A low resistivity indicates a material that readily allows the movement of electrical charge.
IC Design: A subfield of electrical engineering, encompassing the particular logic and circuit design techniques required to design integrated circuits, or ICs. ICs consist of miniaturized electronic devices built into an electrical network on a monolithic semiconductor substrate by photolithography.