As electronic devices around the world become smaller and smaller, the size or thickness of devices made using traditional electronics will be limited. This is also true for consumers who want to build transparent, flexible electronics, as many traditional electronic networks are not designed in this manner. So, what's the answer? Well, there are different answers depending on the part of the device that needs to be miniaturized. With nanotechnology, flexible and transparent screens, batteries, capacitors and circuit boards can become more efficient and smaller/more flexible; more aspects of electronics are being continually influenced by nanomaterials. However, we are focusing here on a specific nanomaterial that shows a lot of promise in electronics and nanoelectronics: nanowires.

What is a nanowire?

Nanowires are very long and thin nanomaterials. In technical terms, this means that they have a high aspect ratio. Considering that this is a geometry similar to that of conventional wires, they have great potential in electronics and nanoelectronic devices. Nanowires are highly conductive materials, but given their size, they are not as conductive as larger electronics, but their small size makes them very useful. Nanowires are also one-dimensional (1D) nanomaterials. This means that electrons within the nanowire are confined to one dimension and prevented from moving in the other two dimensions - a quantum confinement you find in many nanomaterials because their small size brings about interesting quantum phenomena. Because electrons can only move in one dimension, electrons in nanowires can only move along the long axis - just like traditional electron wires.

The state of electrons in nanowires is indeed different compared to that in bulk materials. Due to the quantum effects of nanowires, the electrons in nanowires will occupy discrete bands rather than a continuous state. Even though each electron is quantum confined - because the potential wells within the nanowire are close to each other - they can be connected by electrons tunneling between the potential wells. This allows electrons to flow between the traps with minimal impedance. This is the dominant factor in their high electrical conductivity. Nanowires can also be bundled together to increase the degree of electrical conductivity possible in a small localized space, and they can be easily integrated into other material matrices to make them conductive.

In contrast to traditional metallic wires, which are completely dependent on copper due to its conductive properties, many different types of nanowires exist. Nanowires can consist of superconducting materials such as yttrium barium copper oxide (YCBO) or metals (including platinum, silver, gold and nickel) or semiconductors (such as gallium arsenide, silicon and indium phosphide) or insulating materials (such as silicon dioxide and titanium dioxide). These are just a few of the most common examples, as nanowires with novel compositions are emerging all the time. In many cases, many nanowires are essentially inorganic from a chemical standpoint.

Nanowires for a wide range of applications in electronics

The greatest potential of nanowires lies in transistors. Due to their high aspect ratio, it is easy to create dielectric gates around nanowires, which allows them to be turned off and on with relative ease. In addition, due to their size, nanowire transistors are not adversely affected by the same level of impurities as bulk transistors, which makes fabrication cheaper and easier because impurity-free materials are not necessarily required. While many nanowire transistors require semiconductor junctions to help control electron flow, some devices do not contain junctions and electron flow is controlled by a circular structure of squeezed nanowires that increases or decreases electron flow depending on whether the ring is in a "relaxed" or "squeezed" state. state.

There are a number of other applications that may benefit in the future. These include flexible electronics and sensors. There is currently a lot of buzz about flexible electronics, especially because there is something very science fictional about it. When people realized that two-dimensional materials could be used for batteries and touchscreens in electronic devices, they started to get excited about flexible electronics. But these components still need to be connected, and that's where nanowires can come into play. Nanowires can be combined into a variety of thin-layer material composites and can act as flexible conductive media. They can then be bent with any other flexible material in the device without affecting the conductivity of the device. In addition, because they are so small, they are virtually invisible and do not constitute the optical transparency of the screen. The field of flexible electronics may include consumer electronics such as cell phones and laptops, as well as wearable devices for medical and fitness applications.

For sensors, many people know that nanomaterials have enhanced the sensing capabilities of all types of sensors. To date, nanowire sensors have been used to measure a variety of chemicals, gases and biomolecules, as well as pH values. Nanowire-based sensors have a sensing mechanism very similar to the way field-effect transistors (FETs) work. In nanowire-based sensors, the nanowires are typically made of semiconductor materials. When an interaction occurs between an acceptor on the sensor surface and a target molecule, it causes a change in the surface potential, which changes the local density of holes and/or electrons in the semiconductor - which then produces a detectable and measurable change.

Conclusion

Nanowires offer a way to miniaturize electronic devices and create more flexible electronics by acting as a conductive medium between components in a device. Much like conventional wires, the electrons in nanowires will flow along the long axis of the material, and nanowires can be bundled together to produce higher electrical conductivity in a smaller area of space. Nanowires can be used in a wide variety of applications in electronics, most commonly in transistors, but also in flexible and wearable electronics, transparent electronics and sensors.