U.S. scientists develop scale for measuring perovskite energy


With research teams all over the world working on solar cells and other electronic devices utilizing perovskite materials, using standardized measurements to document their behavior and performance is an important step toward further improvements.

In a paper entitled ‘Scaling law for excitons in 2D perovskite quantum wells’, published in the journal Nature Communications, A team led by Rice University and Los Alamos National Laboratory has developed a scale to determine the binding energy of excitons, and thus the bandgap structures, in perovskite wells. This scale, according to Rice Unversity, could assist scientists in developing new semiconductor materials.

“Understanding the nature of excitons and generating a general scaling law for exciton binding energy is the first fundamental step required for the design of any optoelectronic device, such as solar cells, lasers or detectors,” said Aditya Mohite, who is set to become an associate professor of chemical and biomolecular engineering at Rice University.

Materials in the study were synthesized in a lab at Northwestern University, and brought to Rice  University’s lab where they were exposed simultaneously to ultra-low temperatures, high magnetic fields and polarized light – achieved using the lab’s unique spectroscopy tool Rice Advanced Magnet with Broadband Optics (RAMBO).

Combined with a computer model, the experimentation allowed the researchers to create a scale predicting exciton binding energies in 2D or 3D perovskites at any thickness.

“This work represents a fundamental and nonintuitive result where we determine a universal scaling behavior for exciton binding energies in Ruddlesden-Popper 2D hybrid perovskites,” Mohite said. “This is a fundamental measurement that has remained elusive for several decades, but its knowledge is critical before the design of any optoelectronic devices based on this class of materials and may have implication in the future for design of, for example, zero-threshold laser diodes and multifunctional hetero-material for optoelectronics.”