Berlin 2018 – wissenschaftliches Programm

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 61: Focus: Fundamental Physics of Perovskites II - organized by Lukas Schmidt-Mende and Vladimir Dyakonov

CPP 61.1: Topical Talk

Donnerstag, 15. März 2018, 09:30–10:00, C 130

Approaching the Shockley-Queisser Limit with Interface Control in Halide Perovskites — •David Ginger — University of Washington, Seattle, USA

Although remarkable gains in performance have been demonstrated for halide perovskite semiconductors, most current perovskite solar cells are still limited by non-radiative recombination losses. In this talk, I will focus on uncovering and eliminating these loss processes. Experiments suggests that electrical heterogeneities in both the perovskite active layer, as well as the perovskite/electrode interface, affect carrier diffusion and non-radiative recombination processes within perovskite solar cells. I will describe both confocal and conductive atomic force microscopy (cAFM) to explore the role of heterogeneities and grain boundaries on lateral carrier transport, and will demonstrate varying degrees of grain boundary opacity to carrier transport depending on the structure. We will also discuss both ligand exchange and cation exchange experiments in the context of tailoring the surface properties of halide perovskite thin films. We show that with controlled passivation of the perovskite surfaces we are able to obtain carrier lifetimes and PL intensities in solution-processed thin films that rival those in the best single crystals, achieving over 90% PL internal quantum efficiency and quasi-Fermi level splittings that exceed 96% of the Shockley-Queisser limit under illumination. Combining these results with experiments demonstrating contact-induced losses in many common perovskite architectures, we then explore new contact materials and their potential for increased efficiency.