The interface degradation of planar organic–inorganic perovskite solar cell traced by light beam induced current (LBIC)

Abstract

The light beam induced current (LBIC) method was adopted to nondestructively map the photoresponse of real planar organic–inorganic hybrid perovskite solar cells (PSCs). It is found that the photoresponse of the devices is not uniform even though the morphology of the perovskite films from scanning electron microscope (SEM) or atomic force microscope (AFM) images shows uniform character. This nonuniformity of the photoresponse of the devices is further exacerbated after degradation, which can be well traced by the LBIC method. The indistinguishable morphology change during the device degradation indicates that the degradation of the device is not mainly determined by the morphology of the perovskite layer, but by the interface between the perovskite and the electrode. By using the LBIC method, the worse performing area of the device is identified and then removed accordingly. The current density of the device can be enhanced from 19.44 mA cm⁻² to 21.72 mA cm⁻² after this clearance of the worse performing area.