Organic-inorganic hybrid perovskite (OIHP) solar cells have gained significant attention in recent years due to their ever-increasing power conversion efficiencies. Their low-cost fabrication procedures, large career diffusion lengths, and high absorption coefficients make OIHPs attractive candidates for highly efficient solar cells. However, defects and grain boundaries within OIHPs limit their performance, and more detailed studies showing how these structural features influence carrier transport and recombination are needed in order to guide the rational design of improved devices. Here, we apply high-resolution Scanning Electrochemical Cell Microscopy (SECCM), a pipet-based electrochemical imaging platform, to map photoelectrochemical reactions occurring across the surface of single crystal perovskite electrodes. Spatial variations in photoelectrochemical reaction rates reveal how surface faceting impacts heterogeneous electron transfer rates and how defects and grain boundaries within OIHPs limit transport. These electrochemical imaging studies will help establish important connections between the morphology and performance in OIHP materials and, more broadly, the utility of electrochemical imaging techniques for probing the behavior of photogenerated carriers in emerging semiconducting material systems.

Probing facet-dependent photoelectrochemistry on single crystal perovskite electrodes.

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.