Book/Dissertation / PhD Thesis

FZJ-2020-03959

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Time-Resolved Photoluminescence on Perovskite Absorber Materials for Photovoltaic Applications

Staub, F. (Corresponding author)FZJ*

2020
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 978-3-95806-503-1

Please use a persistent id in citations: http://hdl.handle.net/2128/26432

Abstract: Time-resolved photoluminescence has become a commonly used tool to mainly determine charge-carrier lifetimes in metal halide perovskites. In this thesis, I investigate photoluminescence transients regarding radiative and non-radiative charge-carrier recombination as well as charge-carrier separation by diffusion. Additionally, I focus on the so-called photon recycling effect. Photon recycling refers to the self-absorption of photons, which have been generated by radiative recombination of excited states, within the absorber material itself. As photon recycling is directly linked with the radiative recombination process, the presence of photon recycling is actually masked and not obvious in photoluminescence transients. Here, I reveal the presence of photon recycling in thin-film perovskites by reporting that the obtained apparent radiative recombination rate can be manipulated by modifying only the optical design of the sample stack; i. e. tuning the probability of photonreabsorption in the absorber layer by altering the light management in the stacks. Furthermore, perovskite single crystals have been investigated by time-resolved photoluminescence to study the impact of reabsorption in more detail. I show that photon recycling supports the preservation of charge carriers but does not enable efficient charge-carrier transportation over long distances. Spectral shifts observed in the transient measurements are the result of altering reabsorption characteristics as the recombination zone expands over time into the bulk mainly as a consequence of charge-carrier diffusion. Understanding photon recycling and recombination processes is important for photovoltaic devices as these mechanisms affect the open-circuit voltage. Based only on the findings from time-resolved photoluminescence, I demonstrate how to predict the maximum attainable open-circuit voltage, which the investigated perovskite absorber layer embedded in a solar cell stack could ideally provide. This approach helps to estimate the photovoltaic potential of any absorber layer based on its material quality without the need of fabricating an entire solar cell first.

Note: Universität Duisburg, Diss., 2020

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Contributing Institute(s):

1. Photovoltaik (IEK-5)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

Appears in the scientific report 2020

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Database coverage:
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