Researchers have created a new type of solar cell that replaces silicon with a crystal called perovskite. This design converts sunlight to electricity at efficiencies similar to current technology but at much lower cost.
A new design for solar cells that uses inexpensive, commonly available materials could rival and even outperform conventional cells made of silicon.
Writing in the Oct. 21 edition ofScience, researchers from Stanford and Oxford describe using tin and other abundant elements to create novel forms of perovskite – a photovoltaic crystalline material that’s thinner, more flexible and easier to manufacture than silicon crystals.
“Perovskite semiconductors have shown great promise for making high-efficiency solar cells at low cost,” said study co-author Michael McGehee, a professor of materials science and engineering at Stanford. “We have designed a robust, all-perovskite device that converts sunlight into electricity with an efficiency of 20.3 percent, a rate comparable to silicon solar cells on the market today.”
The new device consists of two perovskite solar cells stacked in tandem. Each cell is printed on glass, but the same technology could be used to print the cells on plastic, McGehee added.
“The all-perovskite tandem cells we have demonstrated clearly outline a roadmap for thin-film solar cells to deliver over 30 percent efficiency,” said co-author Henry Snaith, a professor of physics at Oxford. “This is just the beginning.”
Tandem technology
Previous studies showed that adding a layer of perovskite can improve the efficiency of silicon solar cells. But a tandem device consisting of two all-perovskite cells would be cheaper and less energy-intensive to build, the authors said.
“A silicon solar panel begins by converting silica rock into silicon crystals through a process that involves temperatures above 3,000 degrees Fahrenheit (1,600 degrees Celsius),” said co-lead author Tomas Leijtens, a postdoctoral scholar at Stanford. “Perovskite cells can be processed in a laboratory from common materials like lead, tin and bromine, then printed on glass at room temperature.”
But building an all-perovskite tandem device has been a difficult challenge. The main problem is creating stable perovskite materials capable of capturing enough energy from the sun to produce a decent voltage.
A typical perovskite cell harvests photons from the visible part of the solar spectrum. Higher-energy photons can cause electrons in the perovskite crystal to jump across an “energy gap” and create an electric current.
A solar cell with a small energy gap can absorb most photons but produces a very low voltage. A cell with a larger energy gap generates a higher voltage, but lower-energy photons pass right through it.
An efficient tandem device would consist of two ideally matched cells, said co-lead author Giles Eperon, an Oxford postdoctoral scholar currently at the University of Washington.
“The cell with the larger energy gap would absorb higher-energy photons and generate an additional voltage,” Eperon said. “The cell with the smaller energy gap can harvest photons that aren’t collected by the first cell and still produce a voltage.”
The smaller gap has proven to be the bigger challenge for scientists. Working together, Eperon and Leijtens used a unique combination of tin, lead, cesium, iodine and organic materials to create an efficient cell with a small energy gap.
“We developed a novel perovskite that absorbs lower-energy infrared light and delivers a 14.8 percent conversion efficiency,” Eperon said. “We then combined it with a perovskite cell composed of similar materials but with a larger energy gap.”
The result: A tandem device consisting of two perovskite cells with a combined efficiency of 20.3 percent.
“There are thousands of possible compounds for perovskites,” Leijtens added, “but this one works very well, quite a bit better than anything before it.”
Seeking stability
One concern with perovskites is stability. Rooftop solar panels made of silicon typically last 25 years or more. But some perovskites degrade quickly when exposed to moisture or light. In previous experiments, perovskites made with tin were found to be particularly unstable.
To assess stability, the research team subjected both experimental cells to temperatures of 212 degrees Fahrenheit (100 degrees Celsius) for four days.
“Crucially, we found that our cells exhibit excellent thermal and atmospheric stability, unprecedented for tin-based perovskites,” the authors wrote.
“The efficiency of our tandem device is already far in excess of the best tandem solar cells made with other low-cost semiconductors, such as organic small molecules and microcrystalline silicon,” McGehee said. “Those who see the potential realize that these results are amazing.”
The next step is to optimize the composition of the materials to absorb more light and generate an even higher current, Snaith said.
“The versatility of perovskites, the low cost of materials and manufacturing, now coupled with the potential to achieve very high efficiencies, will be transformative to the photovoltaic industry once manufacturability and acceptable stability are also proven,” he said.
The Latest on: Perovskite solar cell
[google_news title=”” keyword=”perovskite solar cell” num_posts=”10″ blurb_length=”0″ show_thumb=”left”]
via Google News
The Latest on: Perovskite solar cell
- Low-energy process for high-performance solar cellson May 7, 2024 at 3:17 pm
Solar energy offers one solution, with scientists devising ever more efficient materials for capturing sunlight. Perovskite solar cells have emerged as a promising alternative to conventional, silicon ...
- UCSB pioneers a low-energy process for high-performance solar cellson May 6, 2024 at 8:05 am
Researchers at UC Santa Barbara developed a way to make perovskite films at room temperature. This material has emerged as a promising alternative to conventional, silicon solar cells.
- NREL interactive chart of solar cell efficiency now including ‘hybrid tandems’on May 6, 2024 at 4:09 am
The new cell category includes perovskite/silicon, perovskite/CIGS, III-V/silicon and perovskite/organic tandem PV devices. It will list the absolute record efficiency for all-perovskite, two-terminal ...
- Improving perovskite solar cell performance with conductive adhesive inkon May 6, 2024 at 3:23 am
Conceived by researchers from Iran, the new conductive adhesive ink is made of polymethyl methacrylate (PMMA) and is used as an interlayer between the cell's hole transport layer and carbon foil. It ...
- IIT Roorkee’s Perovskite Start-Up Wins IOCL Start-Up Challenge Grant for Advancing Solar Window Technologyon May 5, 2024 at 9:32 pm
A Collaborative Journey of Innovation at IIT Roorkee Revolutionizing Solar Energy with Innovative Window Technology Transforming Buildings into Powerhouses: The Rise of Solar Windows Pioneering the ...
- Researchers pioneer a low-energy process for high-performance solar cellson May 5, 2024 at 5:00 pm
Solar energy offers one solution, with scientists devising ever more efficient materials for capturing sunlight. Perovskite solar cells have emerged as a promising alternative to conventional, silicon ...
- Perovskite Solar Cells: What Are They & How Do They Work?on May 4, 2024 at 7:15 am
This renewable energy technology has shown huge potential for over a decade, if only a few large obstacles could be overcome on the road to market.
- Can perovskite solar cells outshine silicon and revolutionize solar energy?on May 3, 2024 at 3:06 am
For decades, the familiar blue rectangles of silicon solar panels have dominated rooftops across the globe with the increasing adoption of solar energy. While these panels have become a reliable ...
- New material for perovskite solar cells can improve their stability and efficiencyon May 2, 2024 at 12:35 pm
A team of chemists from Kaunas University of Technology (KTU), Lithuania developed a new material for perovskite solar cells. After polymerisation, it can be used as a hole transporting layer in both ...
via Bing News