In a photovoltaic cell,light generates opposite charges in the active layer. The charges must then be separated as quickly as possible to maintain them from recombining. Positive charges are driven by a built-in electric field to one metallic contact, while negative charges migrate in the opposite direction to another electrode. Using a unique ultra-fleet spectroscopic technique, or EPFL scientists have now been able to track the fate of charged pairs in an advanced type of solar cells currently under intense research. The work is published in Nature Communications.
Source: phys.org