Ames Laboratory researchers can ‘see’ light hitting a solar cell

A new paper published by the Ames Laboratory discusses a technique which could improve scientists understanding of charge carrier and atom movement in the class of photovoltaic materials known as organometal halide perovskites.

Using time resolved low frequency spectroscopy in the terahertz spectral region, researchers explored the photo-excitations of the organometallic materials.

“These devices are so new and so unique that the mechanism by which a particle of light converts to charge carriers and how they move in a concerted way for energy conversion is not well understood,” said Ames Laboratory scientist Jigang Wang. “That is the most fundamental process in solar cell and photovoltaic technologies.”

The researchers sought to learn how the generation and dissociation of bound electron and hole pairs, as well as the quantum pathways and time interval of the event. “If we can measure such a memory in the charge transport and energy migration in these materials, we can understand and control it, and have the potential to improve them by learning from mother nature.”

Wang also pointed out that the paper draws on experience from several fields including material design, computational theory and spectroscopy. “Having those capabilities in one place is what makes Ames Laboratory one of the most forward-looking places in this kind of photonic materials research.”