The design of devices for more efficient and renewable energy sources is at the forefront of scientific research. One approach uses Ruddlesden-Popper perovskites — a type of layered material made from alternating sheets of inorganic and organic components. These materials are potentially ideal for several applications, including LEDs, thermal energy storage, and solar-panel technology. In a study that could bolster the efficiency of solar technologies — including existing solar cells — researchers at the University of Utah found a connection between the phase transitions of perovskite material and the material’s emissive properties. This, according to the researchers, introduces a form of dynamic control, or tunability, that offers multiple benefits for technological applications. The researchers used temperature-dependent absorption and emission spectroscopy, as well as X-ray diffraction, to study the phase transition behaviors of perovskites. Because perovskites contain both organic and inorganic components, the organic layers undergo phase transitions that influence the structure of the inorganic layers. A diagram from the research study indicates the effect of phase transitions in perovskites. The organic component goes from a crystalline state (left) to a more disordered state (right) upon changes in temperature. A blueshift indicates a shortening of the light emission wavelength, whereas a redshift indicates a lengthening. Courtesy of the University of Utah. “There are these almost greasy chains that kind of crystallize together. When you hit a certain temperature, those will essentially melt and become more disordered,” said senior author of the study, Connor Bischak. “The melting process influences the structure of the inorganic component, which controls how much light is emitted from the material and its wavelength.” The scientists observed differences in distortion within the inorganic component that resulted in controllable changes to the light’s wavelength, which is a crucial part of designing tunable LEDs and other electronic devices. This tunability is a strength for applications in energy storage technology; according to Bischak, the emission wavelength of perovskites can be tuned from ultraviolet up to near-infrared. Additionally, perovskites can undergo repeated thermal cycling with minimal degradation, ensuring greater efficiency and longevity compared to current industry-standard materials. While silicon has long been the standard material for solar cells, it faces limitations due to its energy-intensive manufacturing process and ongoing supply chain issues. In contrast, perovskites are solution-processable materials. “What [the work shows] is you basically dissolve all these precursor chemicals in a solvent, and then you can make your solar cell almost like printing with ink,” Bischak said. “It produces an efficient solar cell material that’s better than silicon.” An added benefit of the work is that existing silicon solar cell technology can be retrofitted with perovskites to significantly increase their efficiency. Funding for the research was provided by the U.S. Department of Energy. The research was published in Matter (www.doi.10.1016/j.matt.2025.102146).
