Perovskite solar cells have been in talks of renewable energy for years now; however, it looks like the tables are turning and something called kesterite is taking over. With a world-record efficiency of 13.2% for kesterite solar cells, researchers from the University of New South Wales (UNSW) have demonstrated that this technology is not only feasible but also a serious contender for the future of sustainable energy.
More and more people around the world are depending on photovoltaics (PVs), which are devices that can turn sunlight into electrical power, to provide electricity. Engineers that specialise in renewable energy are searching for materials and methods that could assist lower the cost of solar technology while increasing their power conversion efficiencies (PCEs).
How is kesterite better than perovskite?
As a tandem top-cell candidate, kesterite Cu2ZnSnS4 CZTS, a compound of copper, zinc, tin, and sulphur, is a high-bandgap thin film, flexible material that presents a promising substitute for the more extensively researched perovskite due to its long-term performance, low manufacturing costs, and environmental friendliness.
Wide-bandgap kesterite Cu2ZnSnS4 (CZTS), a semiconductor with a huge energy gap that may allow for more efficient light absorption, is a promising material for the development of PVs. CZTS is non-toxic and composed of components that are widely available on Earth, unlike silicon, which is now the main material used to build PV technology. As a result, it might be applied to produce more economical and environmentally friendly solar cells.
Even though perovskite has demonstrated remarkable efficiency gains in recent years, a number of issues have prevented it from becoming widely used. The two main issues are toxicity and stability since lead, a hazardous heavy metal that can harm the environment, is frequently present in perovskite cells and they decay rapidly.
Kesterite is better than perovskite, but it also poses some challenges
Notwithstanding their benefits, CZTS solar cells have only demonstrated a maximum efficiency of 11% thus far, which is far lower than that of their silicon counterparts. A process called carrier recombination, which involves the recombination of photo-generated electrons and holes before they can be collected to generate energy, is largely to blame for their restricted performance.
Using a process called hydrogen annealing, researchers at the University of New South Wales in Sydney investigated the prospect of reducing the impacts of carrier recombination in wide-bandgap kesterite solar cells. It has been at the top of its game; however, enhancing the carrier collecting efficiency of this material has been a major challenge.
The 22nd century’s solar panels will soon be available
The potential of kesterite is becoming increasingly apparent as research into it develops. It is a perfect fit for next-generation solar panels because of its inexpensive ingredients, non-toxic makeup, and increasing efficiency. With more improvements, kesterite may soon compete with or perhaps outperform conventional silicon and perovskite cells, according to scientists.
The ramifications are extensive: kesterite may contribute to the global shift to renewable energy, particularly in underdeveloped countries where sustainability and affordability are essential. Kesterite solar panels have the potential to revolutionise the solar business by reducing dependency on hazardous elements like lead and boosting energy efficiency.
Solar energy has a bright future
According to an article by Sun, their future work is to increase the wide-bandgap CZTS solar cells’ efficiency above the 15% standard while preserving their benefits for the environment and the economy. This entails improving the hydrogen annealing procedure and investigating additional methods to enhance the material’s optoelectronic characteristics.
Prof. Xiaojing Hao and her team from UNSW’s School of Photovoltaic and Renewable Energy Engineering said,
“The big picture here is that we ultimately want to make electricity cheaper and greener to generate. 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.”