Imaging Toolsets to Elucidate Degradation Pathways in Perovskite Optoelectronic Devices

Halide perovskites are promising candidates for the next generation of optoelectronic devices. However, their operational stability needs to be extended and, to do so, degradation and failure modes need to be fully understood.

Here, I will present our group's recent results in which we use different optical, electron and X-ray imaging modalities to probe perovskite solar cells, LEDs and X-rays detector devices, including operando measurements. I will show examples using single-junction and tandem solar cell structures to identify issues with phase impurities and interfaces. Tracking blue LEDs in operando reveals the critical role at the interfaces in driving electrochemical reactions. Imaging the bulk and the surface region of single crystals for X-ray detectors reveals the interplay between performance, ion migration and stability. These powerful toolsets allow elucidation of degradation modes, thus guiding further performance and stability improvements.