The new method creates materials that could create the next generation of solar cells
(Nanowerk News) Perovskites, a family of materials with unique electrical properties, hold promise for use in a variety of fields, including the next generation of solar cells. A team of Penn State-led scientists created a new process for making large perovskite devices that is more cost- and time-efficient than previously possible and which they say could accelerate future discoveries of the material.
“This method we developed allows us to easily fabricate very large bulk samples in minutes, rather than days or weeks using traditional methods,” said Luyao Zheng, postdoctoral researcher in the Department of Materials Science at Penn State and lead author. the study. . “And our material is of high quality — its properties can compete with single crystal perovskite.”
The researchers used a sintering method called the electric and mechanical field-assisted sintering technique (EM-FAST) to fabricate the devices. Sintering is a process commonly used to compress fine powders into a solid mass of material using heat and pressure.
A typical process for making perovskite involves wet chemistry — the material is melted in a solvent solution and then solidifies into a thin film. These materials have excellent properties, but the approach is expensive and inefficient for making large perovskites and the solvents used may be toxic, scientists say.
“Our technique is the best of both worlds,” said Bed Poudel, a research professor at Penn State and co-author. “We get single-crystal-like properties, and we don’t have to worry about size limitations or contamination or toxic yields.”
Because it uses dry materials, the EM-FAST technique opens the door to introducing new dopants, materials added to match the properties of the device, that are incompatible with the wet chemistry used to make thin films, potentially accelerating the discovery of new materials, the scientists said.
“This opens up possibilities for designing and developing new classes of materials, including better thermoelectric and solar materials, as well as X-ray and X-ray detectors,” said Amin Nozariasbmarz, research assistant professor at Penn State and co-author. “Some of its applications are things we already know about, but because it is a new technique for making new perovskite halide materials with controlled properties, structure and composition, there may be room in the future for new breakthroughs from it.”
Additionally, the new process allows layered materials—one powder under the other—to create designer compositions. In the future, manufacturers could design custom devices and then print them directly from dry powder, scientists say.
“We anticipate this FAST perovskite will open another dimension for the synthesis of high-throughput materials, the future manufacture of directly printing devices from powders and accelerate the discovery of new perovskite composition materials,” said Kai Wang, research assistant professor at Penn State and co-author. .
EM-FAST, also known as spark plasma sintering, involves applying an electric current and pressure to a powder to create a new material. The process has a 100% yield — all raw materials go to the final device, compared to 20 to 30% in solution-based processing.
This technique produces perovskite material at a rate of 0.2 inches per minute, allowing scientists to quickly build large devices that maintain high performance in laboratory tests.
The team reports their findings in a journal Nature Communications (“Universal all-solid synthesis for the production of high-throughput perovskite halides”).
Penn State scientists have long used EM-FAST to build thermoelectric devices. The work is the first attempt to make a perovskite material with this technique, scientists say.
“Because of the background we had, we talked and thought we could change some of the parameters and try it with a perovskite,” said Nozariasbmarz. “And that just opened the door to a new world. This paper is the link to that door – to new materials and new properties.
Other Penn State researchers on the project are Wenjie Li and Dong Yang, research assistant professor; Ke Wang, staff scientist at the Materials Research Institute; Jungjin Yoon, Tao Ye and Yu Zhang, postdoctoral researchers; Yuchen Hou, doctoral candidate; and Shashank Priya, former associate vice president for research and director of strategic initiatives and professor of materials science and engineering.
