Carbon Nanotube Application in Electronic Components
Since the discovery of carbon nanotubes by NEC's electron microscopy expert in 1991, carbon nanotubes (CNTs) have been used as a novel nanomaterial with its unique physical and chemical characteristics, important basic research significance and molecular electronics. The potential application value in the field of devices and composites has attracted more and more attention. Its application research mainly focuses on composite materials, hydrogen storage, electronic devices, batteries, supercapacitor field emission displays, quantum wire templates, electron guns and sensors and microscopes. In the field of probes and other fields, many important advances have been made.
Carbon nanotubes can be divided into two types: single-walled carbon nanotubes and multi-walled carbon nanotubes. Single-walled carbon nanotubes (SWCNTs) are formed by rolling a single layer of graphite into a columnar seamless tube. It is a perfectly structured single-molecule material with a diameter ranging from a few nanometers to a few tens of nanometers. The distance between the layers is about 0.34 nm, and the distance between the carbon atom layer and the layer in the graphite is 0.335 nm. It is observed that most of the carbon nanotubes are closed at both ends, and the study shows the cap of the carbon nanotube port. In part, due to the appearance of a pentagonal structure and a large bending rate, the mobility of the single-walled carbon nanotubes may be either metal-type carbon nanotubes or semiconductor-type carbons depending on the helix direction (helix angle) of the hexagonal ring. Nanotubes, and can be characterized by the helical vector parameters (n, m) of carbon nanotubes. When n=m, it is called a chair-type carbon nanotube, which is a metal-type carbon nanotube; when n=0 or m=0, it is called a zigzag-type carbon nanotube; when n and m are unequal integers, The spiral carbon nanotube sawtooth type and the spiral type carbon nanotube may be either a metal type carbon nanotube or a semiconductor type carbon nanotube. If the nm = 3k (k is a non-zero integer), it is a semiconductor type carbon. The nanotubes, otherwise the ends of the metal-type carbon nanotube tubes, are closed by a half-sized corresponding fullerene sphere. Therefore, fullerene (such as O) is strictly a kind of carbon tube, that is, the length of the tube is 0. However, it is necessary to point out that its nature is very different from the carbon tube in the general sense, so It is generally listed separately to study the properties of 2 carbon nanotubes. CNTs have many singular properties, such as thermodynamic properties, field emission characteristics, electrical conductivity, etc., which have attracted great attention from many scientists in the world. Below we simply classify Description Thermodynamic properties CNTs have the same thermal conductivity and unique mechanical properties as diamond. Theoretical calculations show that the tensile strength of carbon nanotubes is 100 times higher than that of steel. The vibration measurements of carbon nanotube cantilever beams can be estimated to have a Young's modulus of about 1 and an elongation of a few percent. Good bendability, can withstand bending deformation and can be bent into small rings. After stress is removed, it can be completely restored to its original state. Pressure does not cause fracture of carbon nanotubes. These excellent mechanical properties make them with potential application prospects in many fields.
The use of CNT as a field emission electrode material and its excellent field emission electrode characteristics, make the field emission flat panel display thinner, brighter and clearer, revolutionizing the flat panel display technology. Compared with the previous field emission cathode, the advantage is as follows: the tiny diameter of the carbon nanotube has a sharp emitting tip, and it has good electrical conductivity, so the carbon nanotube tip is easy to form a strong electric field, which is very favorable for electron field emission; the electron emission function of carbon nanotube is low, about 1. (The emission characteristics of the carbon nanotubes are very stable, a metal-type carbon nanotube is grown on the Au electrode on the Si/Si2 substrate, and then the probe of the AFM is used. Drag the carbon nanotubes in the direction of the arrow to create two strong bends. A carbon nanotube with a length of about 25 nm between them forms a "Coulomb Island".
Bachtold and some other experts produced a FET-based demonstration circuit based on single-walled carbon nanotubes. The transistors made of single-walled carbon nanotubes have high efficiency, fast switching, room temperature, etc., and the departmental circuit design can integrate multiple devices into a single chip.
Selecting a single carbon nanotube from a multi-walled carbon nanotube and a single-walled carbon nanotube bundle by a simple and reliable method, and gradually oxidizing from the outside to the inside by applying an electric current to both ends of the carbon nanotube. The layer is peeled off step by step and the properties of each layer are determined, and then a single layer having the desired properties is selected. This process can select a single layer which is metallic or semiconducting from each layer of the multi-walled carbon nanotubes, and can be obtained from a single method by a similar method. A semiconductor single-walled carbon nanotube is selected from the wall carbon nanotube bundle to form a nano-FET array to form an integrated circuit.
Carbon nanotube-based electronic devices are the core of carbon nanotube electronics. The successful construction of these devices has made the development of carbon nanotube electronics a big step forward. When applied to practice and further constitute an integrated circuit for carbon nanotubes, carbon nanotube electronics will be put into practice despite the enormous challenges, but the huge rewards for solving the problem are encouraging.
This article is from Allicdata Electronics Limited