As a unique form of carbon that is so thin it is considered two-dimensional, graphene is a special material that is flexible, transparent, stronger than steel, and both electrically and thermally conductive.
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Understandably, graphene is seen as a highly disruptive material that can be applied in many areas, such as medicine and transportation. Graphene holds significant potential when it comes to solar power technology because this kind of technology speaks to many of graphene’s unique qualities.
What Makes the Prospect of Using Graphene in Solar Panels So Promising?
High flexibility, tensile strength, thermal stability, transparency, and electrical conductivity make using graphene in solar panels particularly promising.
Pure graphene can be doped with several different types of atoms to convert the carbon material into a semiconductor. But graphene can also be used as an electrode material, and it is very promising as a substitute for tin oxide in transparent solar cells. It can also be applied as a non-reflective coating that boosts light absorption.
As carbon is an easily sourced material, solar cells made with graphene would be economically viable in the long term. Additionally, organic materials like graphene tend to absorb ultraviolet and infrared areas of the spectrum, while transmitting the visible part of the spectrum. This quality makes them less noticeable and ideal for use on everyday surfaces.
How Does the Use of Graphene in Solar Panels Compare to Traditional Panels?
While graphene has a number of attractive electrical qualities, it also has structural qualities that make it appealing as a solar panel material. Graphene in solar panel production results in reduced microcrack formation due to the panels undergoing less thermal stress. After they have been installed, solar panels with graphene are more robust and last longer, resulting in a greater return on solar power investment.
Through atomic doping, graphene can be tuned and customized. This opens up all kinds of commercial and academic possibilities. The flexibility and two-dimensional nature of graphene also lend themselves to printable solar cells that are flexible and transparent.
Are There Any Commercial Examples of the Use of Graphene in Solar Panels?
To be clear, the use of graphene in solar panels is a major focus of modern solar research, and graphene is still more commonly seen in research than in the real world. That being said, there are some commercial examples of solar panels that incorporate graphene.
One of the first commercial applications of graphene in solar technology came in 2018 from the Chinese company ZHShine. The company was looking to address the issue of dust accumulation on its solar panels when it developed a graphene coating for the top of the panel. The coding improved the solar panels’ performance and made the surface self-cleaning, eliminating the need for regular dust removal. Seeing the success of that pilot project, ZHShine has expanded its commercialization of graphene in solar panels.
In another commercial example, the company Freevolt commercialized solar panels that use graphene as a transparent electrode near the surface of its solar cells. In addition to being more productive due to the superior conductivity of graphene, these solar panels are more resilient to surface wear and thermal stress, giving them a longer lifespan.
More recently, some commercialization efforts have been focused on the marine sector. The UK company Grafmarine has developed a modular solar panel system called NanoDeck that is suited to marine conditions.
Intended to power shipping vessels, NanoDeck can be customized to fit on the surface of any ship thanks to its modular nature. These solar panels use graphene for both its structural and conductive qualities. While only prototypes of NanoDeck are currently available, the technology is currently going through various trials to assess its true commercial potential.
Researching Flexible, Transparent Graphene Solar Cells
One particularly promising area of graphene in solar panel research involves the development of transparent, flexible solar cells. Graphene is well suited to this application because it is both transparent and electrically conductive, which is a rare natural combination.
Currently, indium tin oxide (ITO) is the most common transparent conductive material used to make solar cells. Unfortunately, ITO is also rigid and brittle. It is also costly and difficult to source.
In addition to being transparent, conductive, robust, and flexible, graphene is also extremely thin. An electrode made from graphene can be only a nanometer thick, much thinner than the standard ITO electrode.
In one study reported by MIT News, researchers were able to develop flexible, transparent solar cells using graphene that compared favorably to similar cells made with ITO. Unfortunately, these cells still did not compare favorably to standard commercial solar cells.
Fundamental Challenges to Using Graphene in Solar Panels
While the use of graphene and solar panels holds significant potential, there are fundamental challenges that must be overcome. The biggest challenge is the lower power efficiency of cells that use graphene compared to cells with traditional semiconductor materials. Simply put, graphene semiconductors absorb less light and generate less electricity. The use of graphene in solar panels is also associated with “photovoltaic leakage” — or the loss of electrons when a cell is exposed to the light.
See More: Project Pursues Ultra Low-Cost, Flexible Perovskite Solar Cells
References and Further Reading
Critchley, L. (2022). The Commercialization of Graphene Solar Cells. EE Times. Available at: https://www.eetimes.com/the-commercialization-of-graphene-solar-cells/
Stauffer, N. (2017). Transparent, flexible solar cells. MIT News. Available at: https://news.mit.edu/2017/mit-researchers-develop-graphene-based-transparent-flexible-solar-cells-0728/
The University of Manchester. Graphene Learn Applications. Available at: https://www.graphene.manchester.ac.uk/learn/applications. Retrieved on December 4, 2023.
