Wednesday, May 15, 2024

Researchers enhance the stability of new material for solar cells

Perovskites are new materials that can both harvest and emit light. These new materials offer exciting potential for technologies that range from solar cells to TV and display screens. Now, researchers have developed a new way of enhancing the stability and performance of a particular type of these materials.

A team of researchers from the University of Missouri, in collaboration with scientists from the University of Western Cape in South Africa and physicists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory, have developed a new way to make hybrid perovskites, a type of material that could have transformational potential in new generations of solar cells.

These are the combination of organic and inorganic semiconducting materials that could form the basis of new solar cells or other electronic devices.

“Organic-inorganic hybrid perovskites have become increasingly attractive to the materials and electronics communities, especially over the past 10 years or so,” said MU professor Suchismita (Suchi) Guha, the lead author of the study. “They have become, in some cases, as efficient as silicon-based solar cells. Additionally, they are also much more versatile than silicon and can be used and tuned for a broad array of applications.”

The team improved the methods for making lead halide perovskites. Previous techniques for making these thin-film perovskites required liquid processing using solvents, which rendered the films susceptible to degradation when exposed to air. With this prior manufacturing process, one of its molecules undergoes a change to its structure, causing performance limitations in real-world operating conditions.

Using the new technique, researchers were able to prevent the change, holding the affected molecule in a stable structure throughout a large temperature range. In addition, the new technique rendered the perovskite air-stable, making it appropriate for a potential solar cell.

“There have been many studies that have looked at ways to try to improve the stability of hybrid perovskites, including diffusion barriers, additive engineering, and chemically inert electrode optimization, but this is one of the first studies to look at the growth method itself as a way to boost the final performance of the device,” Guha said.

To confirm the molecular structure of the perovskite material, Guha and the team used X-ray diffraction measurements at Argonne’s Advanced Photon Source (APS), a DOE Office of Science user facility. “Being able to characterize the perovskite structure at the APS provides a unique window into the possibilities of this functional material,” Karapetrova said.

“Preventing the phase change seems to be the key to ensuring improved device performance,” Guha said. “By maintaining a stable structure throughout the operating temperature window, we show the way to an improved and potentially useful perovskite.”

Journal reference:

  1. Randy Burns, Siphelo Ngqoloda, Stephen C. Klue, Evguenia Karapetrova, Christopher J. Arendse, and Suchismita Guha. Temperature-Dependent Phase Stable Hybrid Halide Perovskite Films by Chemical Vapor Deposition. ACS Applied Electronic Materials, 2022; DOI: 10.1021/acsaelm.2c00449