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.”
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.”
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
via Google News
The Latest on: Perovskite solar cell
- Painting with semiconductorson April 12, 2021 at 5:00 am
AMOLF researchers Lukas Helmbrecht and Wim Noorduin have developed a reactive ink that can be painted on an equally reactive canvas. The ink reacts with the material on the canvas to become a ...
- Solar cells deliver world-record performanceon April 12, 2021 at 3:51 am
It’s a really exciting project about a solar-cell technology that’s the hottest topic in research in the area right now – perovskite solar cells, as they’re called.” What was the outcome? “In terms of ...
- Hair! Coming to a next-generation PV cell near youon April 11, 2021 at 10:14 pm
As if to prove the point, researchers at the Queensland University of Technology (QUT) have used human hair clippings sourced from a Brisbane barbershop to create carbon nanodots that were then ...
- Human hair can boost perovskite solar cell performance, new study findson April 11, 2021 at 8:45 pm
Perovskite solar cells have shown great promise in the eternal global quest to deliver even lower-cost and higher efficiency solar PV electricity, but still face a number of key hurdles to ...
- Stabilization of formamidinium lead triiodide α-phase with isopropylammonium chloride for perovskite solar cellson April 8, 2021 at 2:10 pm
Formamidinium lead triiodide (FAPbI 3) perovskite solar cells (PSCs) are mainly fabricated by sequentially coating lead iodide and formamidinium iodide, or by coating a solution in which all ...
- Carbon dots made from hair boost stability of perovskite solar cellson April 8, 2021 at 12:04 am
Over the past decade or so, gains in efficiency have seen perovskite solar cells become a highly promising technology in the realm of renewable energy, quickly coming to match or even outdo the ...
- Perovskite Solar Cells Market Size Report 2021 by Sales Volume, Price and Segmentation Market Forecast to 2025 Says Absolute Reportson April 7, 2021 at 4:38 am
Apr 07, 2021 (The Expresswire) -- "Final Report will add the analysis of the impact of COVID-19 on this industry." “Perovskite Solar Cells Market” ...
- Homing in on longer-lasting perovskite solar cellson March 30, 2021 at 7:56 am
Over recent years, the usable lifetime of perovskite-based cells has gradually improved from minutes to months, but it still lags far behind the decades expected from silicon, the material currently ...
- International Data Fusion Approach Homing In on Longer-Lasting Perovskite Solar Cellson March 30, 2021 at 3:38 am
A new approach to identifying useful formulations could help solve the degradation issue for these promising new lightweight photovoltaics. Materials called perovskites are widely heralded as a likely ...
via Bing News