Regensburg 2019 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 39: Focus: Controlling Phase Formation Dynamics in Solution Processed Semiconductors - organized by Christoph Brabec, Jens Harting and Hans-Joachim Egelhaaf
CPP 39.9: Talk
Wednesday, April 3, 2019, 18:00–18:15, H14
Phase Formation Dynamics of Mixed-halide Perovskites by Real-time In-Situ Optical and X-ray Spectroscopy — •Justus Just1, Klara Suchan2, Pascal Becker3, Eva Unger2,3, and Thomas Unold3 — 1MAX IV Synchrotron Laboratory, Fotongatan 2, 22484 Lund, Sweden — 2Lund University, Paradisgatan 2, 22350 Lund, Sweden — 3Helmholtz-Zentrum Berlin, Hahn-Meitner-Platz 1, 14109 Berlin, Germany
We present a detailed investigation of the phase formation dynamics of the chlorine derived one-step synthesis of MAPbI3 perovskite. In a specially designed atmosphere controlled in-situ reactor, synchrotron based in-situ quick scanning X-ray absorption spectroscopy (QEXAFS), X-ray diffraction (XRD) as well as X-ray fluorescence (XRF) are applied in combination with in-situ optical reflection and photoluminescence spectroscopy. This enables us to correlate the evolution of the chemical reaction from XAS, the formation of crystalline phases from XRD and the chemical composition from XRF with the evolution of the optoelectronic properties of the film on one single timeline. We observe a delayed formation of crystalline MAPbI3 and attribute it to a concentration threshold in the decreasing chlorine content of the sample. Our results give detailed insight into the formation process and can help to provide a mechanistic understanding of the reactions and intermediates involved. This knowledge can be utilized to optimize synthesis strategies and to tune the optoelectronic properties of organic-metal-halide perovskite semiconductors.