The Perovskite-Info newsletter (January 18, 2022)

Scientists from TU Dresden, collaborating with researchers at Seoul National University (SNU) and Korea University (KU), have demonstrated the role of the re-use of photons ('photon recycling') and light scattering effects in perovskite solar cells, providing a pathway towards high-efficiency solar energy conversion.

The researchers from the Dresden Integrated Center for Applied Physics and Photonic Materials (IAPP) at the TU Dresden observed the role of the photon recycling effect. When a photon is radiated inside re-absorbing semiconductors like perovskites, it can be re-absorbed by the emitter itself and generate a new photon via photoluminescence. Such a process of recursively re-absorbing and re-emitting the photons is called photon recycling. While this phenomenon has been previously demonstrated by several research groups, its practical contribution to the efficiency of perovskite solar cells has been under extensive debate. Based on the devices prepared by the groups in SNU and KU, the IAPP researchers discovered that photon recycling and light scattering effects greatly improve the light emission efficiency by a factor of ~5, significantly improving the photovoltage of perovskite solar cells.