Nav: Home

Researchers advance solar material production

January 27, 2020

PULLMAN, Wash. - A Washington State University team has developed a more efficient, safer, and cost-effective way to produce cadmium telluride (CdTe) material for solar cells or other applications, a discovery that could advance the solar industry and make it more competitive.

The researchers showed they could rapidly grow a large amount of high-purity CdTe material -- a more than kilogram-sized crystal in one day -- which would be considered lightning fast in the industry. The technique, which uses a high-pressure furnace to produce large amounts of the needed crystal feedstock material, is 45 % more cost effective than the industry standard and is scalable, which could make CdTe solar technology less expensive than natural gas. The crystal material produced also has better electrical properties than what is currently available.

Working in collaboration with the National Renewable Energy Laboratory (NREL) and industry partner Nious Technologies, Inc., the researchers report on their work in the Journal of Crystal Growth.

CdTe photovoltaics are a newer technology than popular silicon solar cells and are competitive in terms of efficiency. They also perform better in hot and humid weather. While CdTe solar cells could provide significant advantages in cost and efficiency over silicon, they currently make up less than 10 % of the solar market, mostly at the utility scale. In particular, current production methods are slow, costly, cumbersome and lack the flexibility to customize.

"Right now there is a huge kink in raw material production," said Santosh Swain, research assistant professor with the Institute of Materials Research and a co-author on the paper. "The solar industry has steadily increased device efficiency and fabricating devices, but further efficiency gains and cost reduction require improvement in CdTe material properties."

The current manufacturing process involves cooking the CdTe material in a sealed glass tube to contain the reaction. It takes a long time, the tubes are not reusable, and the silica glass is limited in how much heat, mass, and pressure it can take. Because of concerns about the material exploding, the industry is limited in the size of crystals they can grow. To make solar cells, the crystals are then evaporated onto glass substrate to make very thin films.

The new technique uses a strong graphite crucible, and the material is cooked in a high-pressure Bridgman furnace.  The high-pressure environment completely eliminates the possibility of explosions and also allows the researchers to easily add a high concentration of additional materials, called dopants, during the manufacturing process that improve the material's performance. In 2016, the WSU research team in collaboration with NREL and University of Tennessee dramatically improved CdTe technology by adding phosphorus as a dopant, overcoming a 1 Volt limit that had been pursued for six decades. For this project, the researchers added arsenic as a dopant.

Adding the highly volatile dopants during the feedstock manufacturing process also eliminates the need to dope after film deposition which can cause non uniformity issues, said Tawfeeq Al-Hamdi, a PhD student and lead author on the paper.

"Doping is a key strategy," said co-author Seth McPherson. "At 80 atmospheres of pressure, you can really shove the dopants into the material, and you don't have to worry about them evaporating out of the crystal or otherwise escaping the system."
-end-
The researchers created crystals that are 1.2 kilograms in size, but could potentially create crystals that are up to 20 kilograms.

The project was funded by the Department of Energy.

Washington State University

Related Solar Cells Articles:

Record efficiency for printed solar cells
A new study reports the highest efficiency ever recorded for full roll-to-roll printed perovskite solar cells.
Next gen solar cells perform better when there's a camera around
A literal ''trick of the light'' can detect imperfections in next-gen solar cells, boosting their efficiency to match that of existing silicon-based versions, researchers have found.
On the trail of organic solar cells' efficiency
Scientists at TU Dresden and Hasselt University in Belgium investigated the physical causes that limit the efficiency of novel solar cells based on organic molecular materials.
Exciting tweaks for organic solar cells
A molecular tweak has improved organic solar cell performance, bringing us closer to cheaper, efficient, and more easily manufactured photovoltaics.
For cheaper solar cells, thinner really is better
Researchers at MIT and at the National Renewable Energy Laboratory (NREL) have outlined a pathway to slashing costs further, this time by slimming down the silicon cells themselves.
Flexible thinking on silicon solar cells
Combining silicon with a highly elastic polymer backing produces solar cells that have record-breaking stretchability and high efficiency.
Perovskite solar cells get an upgrade
Rice University materials scientists find inorganic compounds quench defects in perovskite-based solar cells and expand their tolerance of light, humidity and heat.
Can solar technology kill cancer cells?
Michigan State University scientists have revealed a new way to detect and attack cancer cells using technology traditionally reserved for solar power.
Solar cells with new interfaces
Scientists from NUST MISIS (Russia) and University of Rome Tor Vergata found out that a microscopic quantity of two-dimensional titanium carbide called MXene significantly improves collection of electrical charges in a perovskite solar cell, increasing the final efficiency above 20%.
Welcome indoors, solar cells
Swedish and Chinese scientists have developed organic solar cells optimised to convert ambient indoor light to electricity.
More Solar Cells News and Solar Cells Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: The Power Of Spaces
How do spaces shape the human experience? In what ways do our rooms, homes, and buildings give us meaning and purpose? This hour, TED speakers explore the power of the spaces we make and inhabit. Guests include architect Michael Murphy, musician David Byrne, artist Es Devlin, and architect Siamak Hariri.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

What If?
There's plenty of speculation about what Donald Trump might do in the wake of the election. Would he dispute the results if he loses? Would he simply refuse to leave office, or even try to use the military to maintain control? Last summer, Rosa Brooks got together a team of experts and political operatives from both sides of the aisle to ask a slightly different question. Rather than arguing about whether he'd do those things, they dug into what exactly would happen if he did. Part war game part choose your own adventure, Rosa's Transition Integrity Project doesn't give us any predictions, and it isn't a referendum on Trump. Instead, it's a deeply illuminating stress test on our laws, our institutions, and on the commitment to democracy written into the constitution. This episode was reported by Bethel Habte, with help from Tracie Hunte, and produced by Bethel Habte. Jeremy Bloom provided original music. Support Radiolab by becoming a member today at Radiolab.org/donate.     You can read The Transition Integrity Project's report here.