Abstract:
From halide perovskite solar cells, to new polymer electrolytes for batteries, many emerging materials being explored for solar energy harvesting and storage show performance that depends sensitively on nanoscale structure. Rapid advances in the capability and accessibility of scanning probe microscopy methods have made it possible to study processing/structure/function relationships ranging from photocurrent collection, to ion uptake, to photocarrier lifetimes with resolutions on the scale of tens of nanometers or better in these materials. Importantly, such scanning probe methods offer the potential to combine measurements of local structure with local function, and they can be implemented to study materials in situ or devices in operando to better understand how materials evolve in time in response to an external stimulus or environmental perturbation. This talk highlights recent advances in the development and application of both scanning probe and optical microscopy methods to help address such questions while filling key gaps between the capabilities of conventional electron microscopy and newer super-resolution optical methods, with a specific focus on perovskite semiconductors. This talk will emphasize the application of multimodal microscopy to characterize perovskite solar cells, and discuss how these insights led us to surface passivation schemes that can achieve 96% of the Shockley-Queisser quasi-Fermi level splitting in these materials.