Relevance of Graphene: Every 40 minutes, the amount of sunlight that reaches the Earth is enough to light up the planet for one whole year, provided we can harness it, convert it into electricity and manage distribution systems efficiently.
Materials that are good conductors of light are ideally suited for solar cells. Graphene is transparent and and has excellent conductivity. Though it is still not too good at collecting the electrical energy produced in a solar cell, it is just a matter of time before researchers figure out a way to enhance this trait.
We’ve been using silicon to build solar cells but the discovery of newer alternatives are expected to make it an obsolete choice soon. According to a recent study, graphene can be tweaked to generate 2 electrons for every photon of light it receives. So, the amount of electricity being produced out of the current PV devices can be doubled by replacing silicon with graphene.
Electron mobility of graphene is very high at about 250,000 cm2/Vs compared to silicon at 1400 cm2/Vs.
What is Graphene?
Graphene is a 2-d (two-dimensional) material made out of carbon. It’s a monolayer of carbon atoms bonded together in a hexagonal lattice. It is transparent (optical transparency of 97.7%), strong (strongest material tested), flexible and an excellent conductor of electricity (5300 W⋅m−1⋅K−1). Being abundantly available and inexpensive, graphene has an incredible potential to evolve the electrical sector and lead innovations.
When bombarded with carbon containing molecules, graphene can repair holes in its sheets and fill them up completely. It is the only form of carbon in which every atom is exposed to chemical reactions on both sides.
Using graphene in solar panels
One of the major challenges in the solar energy sector is to find more efficient ways to store the energy. In order to solve that, scientist have been working on supercapacitors, trying to make them capable of storing enough energy for practical usage as solar batteries. By combining supercapacitors with a fractal-based design in graphene electrodes, scientist have already achieved 30 times higher storage capacity.
If the electrode is designed and implemented successfully, solar cells linked with superconductors are predicted to have 3000% more storage capacity than what’s possible today. They can be integrated with current solar cells to provide a complete energy harvesting and storage solution.
Graphene electrodes can be used on any object anywhere. We could use them on all the electric devices we use everyday without needing batteries or dependency on the grid. We will no more need charging stations for electric vehicles or hybrid cars.
Self-powered electronic devices that derive energy directly from the sun and never run out of power will soon be a reality if graphene electrodes are implemented commercially.
Most solar cells produced today are based on silicon or inorganic materials. They’ll soon reach their limits and the industry will move towards utilization of organic materials such as perovskite and graphene for manufacturing solar cells on a commercial scale.
Besides, graphene can be doped to increase efficiency and solve numerous other problems in the Energy sector. Graphene has the potential to disrupt the industry by improving existing solar cells or by creating graphene-based photovoltaic cells.