1. Integrated circuits
Graphene possesses desirable properties as an excellent integrated circuit electronic device: high carrier mobility and low noise. In 2011, IBM succeeded in creating the first graphene-based integrated circuit - a broadband wireless mixer, which handles frequencies up to 10 GHz and whose performance is unaffected at temperatures up to 127°C. Graphene nanoribbons have the characteristics of high electrical conductivity, high thermal conductivity, and low noise, and are a choice of interconnect materials for integrated circuits, with the potential to replace copper metal. Some researchers have tried to make quantum dots out of graphene nanoribbons. They change the width of the nanoribbons at specific locations to form quantum confinement. The low-dimensional structure of graphene nanoribbons possesses very important optoelectronic properties: population inversion and broadband optical gain. These excellent qualities enable graphene nanoribbons to be placed in microcavities or nanocavities to form lasers and amplifiers. Studies have shown that graphene nanoribbons can be applied to optical communication systems, and graphene nanoribbon lasers can be developed.
2. Graphene transistors
In 2005, Geim's research group and Kim's research group found that graphene has a high carrier mobility 10 times that of commercial silicon wafers at room temperature, and is little affected by temperature and doping effects, showing room temperature sub-micron scale. Ballistic transport properties (up to 0.3 m at 300 K), the most prominent advantage of graphene as a nanoelectronic device, make room-temperature ballistic field effect transistors very attractive in the field of electronic engineering possible. The larger Fermi speed and low contact resistance help to further reduce the device switching time, and the ultra-high frequency operating response characteristics are another significant advantage of graphene-based electronic devices. With modern technology, graphene nanowires can prove generally capable of replacing silicon as a semiconductor.
3. Transparent conductive electrodes
The good electrical conductivity and light transmission properties of graphene make it have a very good application prospect in transparent conductive electrodes. Touch screens, liquid crystal displays, organic photovoltaic cells, organic light-emitting diodes, etc., all require good transparent conductive electrode materials. In particular, the mechanical strength, flexibility, and light transmittance of graphene are superior to those of the commonly used material, indium tin oxide. By chemical vapor deposition, a large-area, continuous, transparent, high-conductivity few-layer graphene film can be made, which is mainly used in the anode of photovoltaic devices, and achieves an energy conversion efficiency of up to 1.71%; Compared with the fabricated element, it is about 55.2% of its energy conversion efficiency.
4. Thermal conductive material/thermal interface material
Studies have shown that the thermal conductivity (K) of graphene at room temperature has exceeded the limit of bulk graphite (2000 W/m•K), carbon nanotubes (3000~3500 W/m•K) and diamonds. It reaches 5300 W/m•K, far exceeding metal materials such as silver (429 W/m•K) and copper (401 W/m•K). Excellent thermal conductivity and mechanical properties make graphene have great development potential in the field of thermal management. Graphene-based films can be used as flexible heat sink materials to meet the requirements of high-power, high-power LED lighting, computers, satellite circuits, laser weapons, and handheld terminal equipment. Thermal requirements for integrated systems. These research results provide a new perspective for the design of structural/functional integrated carbon/carbon composites.
5. Sensors
The unique two-dimensional structure of graphene makes it have bright application prospects in the field of sensors. The huge surface area makes it so sensitive to the surrounding environment that even a gas molecule adsorption or release can be detected. This detection can currently be divided into direct detection and indirect detection. The adsorption and release processes of single atoms can be directly observed by transmission electron microscopy. The adsorption and release processes of single atoms can be indirectly detected by measuring the Hall effect. When a gas molecule is adsorbed on the graphene surface, a local change in resistance occurs at the adsorption site. Of course, this effect also occurs in other substances, but graphene has the good quality of high conductivity and low noise, which can detect this small resistance change
6. Supercapacitors and Lithium-Ion Batteries
Due to its exceptionally high surface area to mass ratio, graphene can be used as a conductive electrode for supercapacitors. Scientists believe that the energy density of such supercapacitors will be greater than that of existing capacitors. Due to its good conductivity and huge specific surface area, graphene can be widely used in lithium-ion batteries: it can be directly used as the negative electrode of lithium-ion batteries, or it can be compounded with SnO2, Si and other materials as the negative electrode of lithium-ion batteries. The modification of graphene can effectively shorten the charging time of Li-ion batteries and increase the power density of Li-ion batteries.
