Researchers from Spain and Colombia have examined the degradation mechanisms affecting perovskite solar cells, and developed a new method to characterize their performance in an outdoor setting.

The group evaluated the method through outdoor testing on perovskite modules manufactured in a lab. The team expects its findings to offer easier device characterization and better understanding of the degradation mechanisms affecting perovskite solar cells, which are crucial factors in the technology’s development.

Scientists at Stanford University and the Department of Energy’s SLAC National Accelerator Laboratory have used a novel method, based pressure from a diamond anvil cell, to stabilize lead halide perovskites and prevent them from breaking down at room temperature.

The team placed the regular version of the material, prone to instability, in a diamond anvil cell and squeezed it at a high temperature. This treatment reportedly "nudges" its atomic structure into an efficient configuration and keeps it that way, even at room temperature and in relatively moist air.

In a study announced last August, researchers from the Australian National University (ANU) reached an impressive 21.6% efficiency, which they said is the highest achieved for perovskite cells above a certain size. The details of their work, and the techniques used by the research team to achieve the results, have now been explained.

Lead researcher, associate professor Tom White, said the research team achieved the new record by adapting a technique previously used with traditional silicon-based solar cells that removed defects. “A common problem with solar cells is that any defects in the cell can trap electrons, taking away the energy they gained by absorbing sunlight,” associate professor White said. “A way around this is to “passivate” the surface by coating the light absorbing material with a thin layer of another material to reduce defects. But the materials used to reduce defects are often poor conductors of electricity.”