Imec, the leading research hub focused on nanoelectronics, energy and digital technologies and partner in EnergyVille, has been named the coordinator of an ambitious 3-year European Union (EU) funded project called "ESPResSo" (Efficient Structures and Processes for Reliable Perovskite Solar Modules), that gathers known leaders in the field of perovskite PV technology to revolutionize Europe's photovoltaics (PV) industry.

The ESPResSo consortium has been granted over 5 Million by the European Union to overcome the limitations of today's state-of-the-art perovskite PV technology, bring perovskite solar cells to the next maturity level, and demonstrate their practical application.

Researchers at the Max Planck Institute for Solid State Research have found that in a certain perovskite, light not only releases electrons, but also electrically charges atoms. This novel photoeffect is said to be extremely large - ion conductivity increased by a factor of one hundred. For solar cells made from this material, the high light-induced ion conductivity is rather damaging but the consequences can be counteracted. The researchers find the effect ground-breaking in itself, as it makes novel, light-controlled electrochemical applications conceivable, such as batteries directly charged by light.

The research team has examined how light influences the transport of electricity in materials based on the perovskite methylammonium lead iodide (MAPI). In their experiments, the researchers observed that ions, or charged atoms, contribute to conductivity to an unexpectedly high degree when the material is illuminated. Light that influences ion transport has previously been demonstrated in biology: Illumination is able to indirectly alter the permeability of a cell membrane. "Very surprising, however, is the fact that the ionic conduction of crystalline solids can be directly modified and to what extent this is possible," says the research team.

A multi-institutional team of researchers from the Department of Energy’s Oak Ridge National Laboratory, Hunan University and the University of Nebraska–Lincoln used photoluminescence measurements, along with neutron and x-ray scattering, to study the relationship between hybrid perovskite materials' microscopic structure and optoelectronic properties. Neutron scattering has revealed, in real time, the fundamental mechanisms behind the conversion of sunlight into energy in such materials, to gain a better understanding that will enable the design of better solar cells.

By examining the material under varying degrees of temperature, the researchers were able to track atomic structural changes and establish how hydrogen bonding plays a key role in the material’s performance. Unlike their singular silicon or germanium counterparts, hybrid perovskites are made of both organic and inorganic molecules. “The advantage of having both organic and inorganic molecules in a well-defined crystal structure means we can tailor the material by tuning either one group or the other to optimize the properties,” said Kai Xiao, a researcher at ORNL’s Center for Nanophase Materials Sciences. “But even though researchers have been studying these materials for several years, we still don’t fully understand on a fundamental level how the organic components are affecting the properties.”