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Electronic devices have been getting smaller for many years. The use of nanomaterials in electronics has opened the scope of the field, and smaller devices than ever before are now possible due to new nanomaterials being created alongside new advances in nanoscale fabrication techniques and nanoscale patterning techniques.
There is a huge drive to reduce the size of electronic devices in today’s consumer world whilst keeping the same levels of efficiency—or in many cases, higher efficiency levels. There are limits as to how small devices can be made using top-down etching and lithography techniques—although they do have their place in nanoelectronics as efficient ways of patterning the materials used in said devices.
Advances in Bottom-Up Nanofabrication Methods
Advances in bottom up nanofabrication methods—methods which build up the materials, atom by atom from nothing by using vaporized (gaseous) atoms—have enabled much thinner nanomaterials to be created and this has ultimately led to smaller devices being created as a result.
The obvious example is graphene and other 2D materials which are commonly built up using these methods to create a single layer (if a single layer is required, more than one layer of graphene has many different commercial manufacturing options). Therefore, the ability to create single layer materials which are more efficient than the status quo has been one of the key reasons behind the realization of nanoelectronic devices.
Materials that Have Contributed to the Field of Nanoelectronics
While graphene has been a widespread choice due to its high electrical conductivity and charge carrier mobility, there are many other materials that have contributed to the field of nanoelectronics. Nanowires are another good example, as they can conduct electricity in one direction and this has enabled very small circuits to be created which are many times smaller than other electrical conduits, and they can also be manufactured to be used as transistors.
Not all nanomaterials are applicable, and conductive materials are the most widely used. In some cases, insulating materials are used, but these are often used to shield the conductive components and direct the current flow to prevent electronic loss—as losses at this scale can attribute to more errors than in bulk electronic systems.
One of the most common examples of this arrangement is the Van Der Waals heterostructures, which are essentially a ‘sandwich of 2D materials’ where a conductive layer is surrounded above and below by insulating layers. One specific example that is showing a lot of promise is graphene sandwiched between hexagonal boron nitride (h-BN) layers.
Range of Nanoelectronic Devices
But it’s not just the basic electronic components that make up this specific class of electronics. In many cases, more specific electronics make up this class, such as ultra-small yet highly sensitive sensors, data hubs made up of small nanomaterials that can transmit and store small amounts of data in Internet of Nano Things (IoNT) systems, nanogenerators which can harness and store small amounts of energy, memory storage systems, computer chips, small photodetector arrays, and flexible/wearable technologies.
All of these very small devices are now possible due to advances in bottom-up nanofabrication methods, including chemical vapor deposition (CVD), physical vapor deposition (PVD), and atomic layer deposition (ALD), alongside nanolithography and etching methods which can pattern the surface to be more efficient.
An Integral Part of Future Quantum Computing Technologies
There are concerns from some people that the small size of nanomaterials would not produce enough of a current to power many devices. However, the nanomaterials which are conductive are known to have very high electrical conductivities. Moreover, at such small scales, quantum effects come into play and many nanoelectronic devices can be made up of a series of quantum wells (also known as energy potential wells).
Due to the electron tunneling phenomena that occurs between quantumly confined regions where the conduction of electrons is very smooth as there is no electrical resistance between the wells which can then lead to very high conductivities. The ability to realize and exhibit quantum effects means that many nanoelectronic devices could also become an integral part of future quantum computing technologies.
Many nanomaterials are also very stable to high temperatures, pressures, and harsh chemical environments meaning that there are almost no limits (on Earth or in space) to where nanoelectronic devices could be used in the future.
Overall, while nanoelectronic devices are already established, the drive to create smaller and more efficient devices will be realized more and more using nanomaterials and advanced nanoscale fabrication methods and will become some of the key drivers for expanding the electronics industry in the future.