WEB Lead-free Double Perovskite Cs2Au2I6 for Photovoltaic DevicesWednesday (23.09.2020) 15:00 - 15:15 F: Functional Materials, Surfaces, and Devices 1 Part of:
Lead-based hybrid perovskites APbX3 (A = CH3NH3, Cs; X = Br, I) provide excellent optoelectronic properties like tuneable band gaps, high charge carrier mobility and diffusion length and high absorption efficiency for photovoltaic applications. However, the high toxicity and low stability towards environmental factors such as heat, moisture, oxygen and light are still a barrier for the commercialization of lead halide perovskite solar cells. Stable and non-toxic double perovskites A2BCX6 (B = Ag, Cu; C = Bi, Sb) are possible alternatives, but usually have wide and indirect band gaps of over 2 eV. The double perovskite Cs2Au2I6 features a bandgap of 1.35 eV and theoretical studies by Debbichi et al. predict power conversion efficiencies of 20% and short-circuit current densities of 30 mA/cm2. In this work, implementation of the mixed-valent double perovskite Cs2Au2I6 in photovoltaic devices was investigated. Several approaches for thin film deposition were tested and first photovoltaic devices were built.