Google Play icon

Perovskite solar cells get an upgrade

Share
Posted November 8, 2019

Rice University scientists believe they’ve overcome a major hurdle keeping perovskite-based solar cells from achieving mainstream use.

Through the strategic use of the element indium to replace some of the lead in perovskites, Rice materials scientist Jun Lou and his colleagues at the Brown School of Engineering say they’re better able to engineer the defects in cesium-lead-iodide solar cells that affect the compound’s bandgap, a critical property in solar cell efficiency.

A sample all-inorganic perovskite solar cell is a step toward commercial use, according to Rice scientists. Illustration by Jeff Fitlow/Rice University

As a side benefit, the lab’s newly formulated cells can be made in the open air and last for months rather than days with a solar conversion efficiency slightly above 12%.

The Rice team’s results appear in Advanced Materials.

Perovskites are crystals with cubelike lattices that are known to be efficient light harvesters, but the materials tend to be stressed by light, humidity, and heat.

Not the Rice perovskites, Lou said.

“From our perspective, this is something new and I think it represents an important breakthrough,” he said. “This is different from the traditional, mainstream perovskites people have been talking about for 10 years — the inorganic-organic hybrids that give you the highest efficiency so far recorded, about 25%. But the issue with that type of material is its instability.

“Engineers are developing capping layers and things to protect those precious, sensitive materials from the environment,” Lou said. “But it’s hard to make a difference with the intrinsically unstable materials themselves. That’s why we set out to do something different.”

An electron microscope image shows a cross-section of the all-inorganic perovskite solar cell developed at Rice. From top, the layers are a carbon electrode, perovskite, titanium oxide, fluorine-doped tin oxide and glass. The scale bar equals 500 nanometers. Image credit: Lou Group

Rice postdoctoral researcher and lead author Jia Liang and his team built and tested perovskite solar cells of inorganic cesium, lead and iodide, the very cells that tend to fail quickly due to defects. But by adding bromine and indium, the researchers were able to quash defects in the material, raising the efficiency above 12% and the voltage to 1.20 volts.

As a bonus, the material proved to be exceptionally stable. The cells were prepared in ambient conditions, standing up to Houston’s high humidity, and encapsulated cells remained stable in air for more than two months, far better than the few days that plain cesium-lead-iodide cells lasted.

“The highest efficiency for this material maybe about 20%, and if we can get there, this can be a commercial product,” Liang said. “It has advantages over silicon-based solar cells because synthesis is very cheap, it’s solution-based and easy to scale up. Basically, you just spread it on a substrate, let it dry out, and you have your solar cell.”

Source: Rice University

Featured news from related categories:

Technology Org App
Google Play icon
85,468 science & technology articles

Most Popular Articles

  1. New treatment may reverse celiac disease (October 22, 2019)
  2. The World's Energy Storage Powerhouse (November 1, 2019)
  3. "Helical Engine" Proposed by NASA Engineer could Reach 99% the Speed of Light. But could it, really? (October 17, 2019)
  4. Plastic waste may be headed for the microwave (October 18, 2019)
  5. Universe is a Sphere and Not Flat After All According to a New Research (November 7, 2019)

Follow us

Facebook   Twitter   Pinterest   Tumblr   RSS   Newsletter via Email