Advances in solar energy come with the speed of lightning. Universities and companies all strive to find the cheapest and greenest material to make effective solar panels. Heading the race is the University of New South Wales (UNSW) with their new kesterite solar panel, leading them to set a new efficiency record.
Kesterite is the way of the future for solar energy
Solar panels are one of the cleanest forms of alternative energy. However, they are made of silicon, which could provoke polluting spills in their manufacturing process. Scientists are always actively looking for other materials to produce greener solar panels.
Prof. Xiaojing Hao and her team at UNSW have found this material, called kesterite (CZTS), and it is everything that it’s cracked up to be. CZTS is a mixture of several other elements. In a competition with perovskite, CZTS offers significant advantages in terms of environmental friendliness, material abundance, and long-term stability.
Why is kesterite better than perovskite?
Kesterite seems to be the ideal material for solar panels for many reasons. Firstly, it is a natural material. Additionally, it can also be created in laboratories by using copper, zinc, tin, and sulfur. All of these elements are abundantly found and harmless.
Secondly, the cost of manufacturing kesterite is very cheap, and its effectiveness doesn’t waver over long periods. There is some difficulty in compounding CZTS that causes efficiency to decrease, but the researchers at UNSW have come up with a solution.
“Producing CZTS involves heating copper, tin, zinc, and sulfur, but managing defects is key. Our study reveals that hydrogen passivates these defects, improving the material’s ability to convert sunlight into electricity,” says Scientia Professor Xiaojing Hao.
UNSW’s kesterite solar cell breaks the efficiency record
UNSW’s solar cell broke the efficiency record set for cells using this material. Their solar cell reached a conversion efficiency of 13.2%, surpassing the previous record of 11.4%. The reason behind their high efficiency rate is the previously mentioned passivation process with hydrogen.
Although other elements may be more efficient than kesterite in terms of conversion, they have their own disadvantages. Perovskite has a high efficiency potential, but its lifespan is shorter, and it is made of toxic elements, like lead. Regarding silicon, Hao explains the following:
“Silicon modules have almost reached the limit of their theoretical efficiency, so what we are trying to do is answer the question coming from the PV industry as to what the next generation of cells will be made of.”
The huge potential of a kesterite solar cell
The researchers who broke the record believe that kesterite is the perfect material for manufacturing solar panels. With a particular emphasis on its being cost-effective, Hao and her team have placed all of their eggs in the kesterite basket, betting on it as the way to lead the solar-powered future.
Hao believes that they can solve the problems in the manufacturing process of kesterite and enhance its levels of efficiency. The research team targets 15% CZTS efficiency within a year, with commercialization expected by 2030.
“It can take a long time to solve those problems, whereas with CZTS if we can get it to 20% efficiency then I think it will really take off because there are no other limitations since it meets all the criteria for the type of material we want to be using.”
If indeed kesterite is as wonderful as it seems to be, the future of solar energy could be cheaper to manufacture, with a lower impact on the environment, and more appropriate for recycling. All that remains to be seen is if Hao and her team can fulfill their promise of a higher level of efficiency.
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