Eurekalert April 5, 2019
An international team of researchers (Switzerland, Iran) found that the large perovskite capacitances are not classical capacitances in the sense of charge storage, but just appear as capacitances because of the cells’ slow response time. They found that the origin of the apparent capacitance is a slow modification of the current passing the contact of the solar cells, which is regulated by a slow accumulation of mobile ionic charge. A slowly increasing current appears like a negative capacitance in the impedance spectra. The work sheds light on the interaction between the photovoltaic effect in these devices and the ionic conductivity of perovskite materials. Gaining such in-depth understanding contributes to the endeavor to tailored, stable perovskite solar cells…read more. Open Access TECHNICAL ARTICLE
Nyquist plots for different perovskite solar cells, operated under forward bias. Credit: Nature Communications http://dx.doi.org/10.1038/s41467-019-09079-z