Dresden 2020 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 45: Perovskite and photovoltaics I (joint session HL/CPP)

CPP 45.9: Talk

Tuesday, March 17, 2020, 12:00–12:15, POT 251

Highly stable perovskite nanocrystals in polymer micelles — •Juri G. Crimmann, Carola Lampe, and Alexander S. Urban — Nanospectroscopy Group, Nano-Institute Munich, Department of Physics, Ludwig-Maximilians-Universität München, Königinstraße 10, 80539 Munich, Germany

Halide perovskite nanocrystals (NCs) have been synthesized through many approaches. Comprising a variety of geometrical shapes, these NCs exhibit excellent optoelectronic qualities, such as near-unity quantum yields and tunable photoluminescence emission. However, perovskite nanocrystals suffer from stability problems as well as extremely mobile halide ions, both resulting in shifts of the photoluminescence emission and instant degradation in water. By using a polymer-templated synthesis we massively improve the stability and suppress halide ion migration by encapsulating NCs individually instead of entire devices. During our synthesis perovskite NCs are formed inside diblock copolymer micelles. The micelles act not only as nanoreactors, but also encapsulate and passivate the NCs, protecting them from the environment. The stability against water degradation increases significantly. Accordingly, even after 75 days of complete submersion in water, characteristic photoluminescence is observable. Furthermore, we have shown that halide ion migration through the polymer shell is nonexistent. We explore the extension of this synthesis to other perovskite compositions, comparing efficiencies and stability. And finally, we explore strategies for incorporating these highly stable NCs into working optoelectronic devices, such as light-emitting diodes (LEDs).