Department of Chemistry Seminar - David Ginger

The Department of Chemistry presents: David Ginger

University of Washington

Host: Sean Roberts

Title: Passivating Interfacial Defects in Halide Perovskite Semiconductors: From Solar Cells to Quantum Light

Location: NHB 1.720

Perovskite semiconductors are of interest in applications from thin film solar cells to sources of quantum light.  While perovskite semiconductors are often described as remarkably defect tolerant, they are not defect free. Passivating interfaces in perovskite solar cells is widely recognized as a strategy for improving performance of perovskite photovoltaics including open circuit voltage and stability.  Likewise passivating surfaces of perovskite quantum dot emitters is crucial to optimize their efficiency, stability, and linewidth for applications as quantum light sources. This talk will discuss studies of surface and interfacial defects and their passivation in halide perovskites.  We probe recombination with a combination of optical spectroscopy, device measurements, and structural probes, examining both thin films and single nanocrystal quantum dots. We show how popular processing additives can undergo unexpected chemical reactions that alter the growth processes in halide perovskite semiconductors.  We examine the interplay of chemical passivation of the perovskite (removing dangling bonds), with the balance of electronic coupling between the electrode layers and the perovskite (electronic coupling).  We show how this improved understanding can improve applications in both light-harvesting and light-emitting applications.