Since the invention of photovoltaic cells in the 1800s, researchers have finally developed a solar cell that is more efficient and cheaper to produce than its previous form.
"The previous solar cell is based on silicone," said Dr. Matthew Paige, a researcher at the University of Saskatchewan. "It works well, but it's expensive to make."
According to a press release, the new solar cell is based on a type of perovskite. While old cells based on this material yielded only 15 per cent, this new type yields 16 per cent.
In an economic sense, these solar cells may not be able to replace traditional resources, but they can certainly become a strong alternative. They have a range of consumer applications such as lower-cost rooftop arrays, solar lights in the backyard, and various other niche applications.
"The problem (with getting it into the mainstream market) is that there are competing materials and devices," said Paige. "The silicone-based solar cell is well entrenched and dislodging that is quite difficult."
In general, silicone is a very robust material, said Paige. It can stay out in the sun all day without degrading, unlike this new perovskite-based cell. This is because the new cell is made from organic molecules, which can get broken down by the sun.
"These cells are very easy to produce," said Tim Kelly, another member of team that developed the new solar cell. "We coat conductive substrates with solutions of simple chemicals - there are no air-sensitive or high-temperature processing steps. You're basically taking a piece of glass or plastic and dipping it in a beaker."
Therefore, the team still faces the challenge of figuring out how to produce the cells so that they won't be damaged by the elements. According to the same press release, "This means hermetically sealing the cells, coming up with some stabilizing chemistry, or both."
Moreover, compared to traditional forms of energy, 16 per cent energy efficiency isn't that much. Hydrocarbons and nuclear energy, for example, are more energy-dense in comparison and quite a bit cheaper, said Paige.
On the downside, hydrocarbons produce greenhouse gases and are becoming more expensive due to their diminishing reserves. Nuclear energy is good and viable, but is an unsafe resource.
"It may not be as good in terms of overall efficiency, but there's a tradeoff," said Paige. "Solar energy may not be as good, but it's balanced out by so many other competing factors."
Unfortunately, dislodging the current silicone-based solar cell from its various niche markets will prove difficult, especially with the issue of its durability. Nevertheless, Paige is confident that that problem will be resolved eventually. Rather, their main focus is on improving energy output.
"We're working on a process that has good potential to increase the overall efficiency," said Paige. "We don't understand all the details of how this process works, but we can make it better if we did understand it."
