Life and Death of Mixed Metal Halide Perovskites : Mechanism and Consequences of Light Induced Halide Segregation in MAPb(I,Br)3
(2023)- Abstract
- Metal halide perovskites have attracted immense scientific interest due to their outstanding optoelectronic properties over a wide
bandgap range. Applications cover a wide range of optoelectronic devices from solar cells, LEDs and lasers to X-ray detectors.[1,
2] Particularly in combination with existing silicon technology, perovskite-silicon tandem solar cells, which achieve power conver-
sion efficiencies of over 32 %, have the potential to reduce the effective cost of solar cell devices, making them economically viable
over carbon-based energy generation.[1] Despite tremendous efforts, the reliable and stable operation of metal halide perovskites
is still hindered by dynamic phenomena such as current-voltage... (More) - Metal halide perovskites have attracted immense scientific interest due to their outstanding optoelectronic properties over a wide
bandgap range. Applications cover a wide range of optoelectronic devices from solar cells, LEDs and lasers to X-ray detectors.[1,
2] Particularly in combination with existing silicon technology, perovskite-silicon tandem solar cells, which achieve power conver-
sion efficiencies of over 32 %, have the potential to reduce the effective cost of solar cell devices, making them economically viable
over carbon-based energy generation.[1] Despite tremendous efforts, the reliable and stable operation of metal halide perovskites
is still hindered by dynamic phenomena such as current-voltage hysteresis,[3, 4] dynamic defect formation,[5, 6] degradation and
light-induced phase segregation.[7] The high ion mobility of metal halide perovskites has been proposed to be at the core of these
critical instabilities that prevent commercial application. Ion mobility is known to be enhanced under illumination. However, in
single halide systems it is not trivial to detect ion migration. Mixed halide systems therefore provide a unique model system for
monitoring ion migration due to the formation of distinctly different phases under illumination. This provides a unique oppor-
tunity to gain further insight into the relationship between optical excitation and ion migration.
This thesis investigates the phase segregation that occurs upon optical illumination of metal halide perovskites with mixed halides
(bromide and iodide).
In a meta-data study, we analyze over 45 000 solar cell device metrics to explore the contribution of phase segregation to device
performance.
Furthermore, we analyze the mechanism of phase segregation. In this work, we present insights from photoluminescence mi-
croscopy as well as multimodal photoluminescence and X-ray diffraction measurements of the temperature and composition
dependence of phase segregation. We revealed the complexity of the phase segregation process and proposed an alternative kinetic
model to rationalize the entire process.
In addition, we described the X-ray sensitivity of mixed metal halide perovskites and the challenges encountered when using X-
ray-based characterization techniques. In particular, we discovered that X-ray induced defects can alter the photo-stability of metal
halide perovskites, making meaningful characterization of the phase segregation process very complex.
Our results highlight the complex interplay between ion mobility, photostability, and photon-induced defects. We are confident
that these insights will contribute to a detailed understanding of light-induced phase segregation and ion migration in general. We
hope that this understanding will point the way to stable and reliable operation of metal halide perovskite solar cells. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/6dcfcc33-b7b8-4cc1-942a-d70b483e4ed0
- author
- Suchan, Klara LU
- supervisor
-
- Ivan Scheblykin LU
- Eva Unger LU
- opponent
-
- Professor F. Toney, Michael, Univeristy of Colorado Boulder
- organization
- publishing date
- 2023
- type
- Thesis
- publication status
- published
- subject
- keywords
- phase segregation, X-ray diffraction, perovskite, solar cells, photoluminescence
- pages
- 212 pages
- publisher
- Lund University
- defense location
- Kemicentrum: A, Lunds universitet. Join via zoom: https://lu-se.zoom.us/j/7604816886
- defense date
- 2023-05-12 09:00:00
- ISBN
- 978-91-7422-948-6
- 978-91-7422-949-3
- language
- English
- LU publication?
- yes
- id
- 6dcfcc33-b7b8-4cc1-942a-d70b483e4ed0
- date added to LUP
- 2023-04-13 11:41:24
- date last changed
- 2023-04-17 14:38:33
@phdthesis{6dcfcc33-b7b8-4cc1-942a-d70b483e4ed0,
abstract = {{Metal halide perovskites have attracted immense scientific interest due to their outstanding optoelectronic properties over a wide<br/>bandgap range. Applications cover a wide range of optoelectronic devices from solar cells, LEDs and lasers to X-ray detectors.[1,<br/>2] Particularly in combination with existing silicon technology, perovskite-silicon tandem solar cells, which achieve power conver-<br/>sion efficiencies of over 32 %, have the potential to reduce the effective cost of solar cell devices, making them economically viable<br/>over carbon-based energy generation.[1] Despite tremendous efforts, the reliable and stable operation of metal halide perovskites<br/>is still hindered by dynamic phenomena such as current-voltage hysteresis,[3, 4] dynamic defect formation,[5, 6] degradation and<br/>light-induced phase segregation.[7] The high ion mobility of metal halide perovskites has been proposed to be at the core of these<br/>critical instabilities that prevent commercial application. Ion mobility is known to be enhanced under illumination. However, in<br/>single halide systems it is not trivial to detect ion migration. Mixed halide systems therefore provide a unique model system for<br/>monitoring ion migration due to the formation of distinctly different phases under illumination. This provides a unique oppor-<br/>tunity to gain further insight into the relationship between optical excitation and ion migration.<br/>This thesis investigates the phase segregation that occurs upon optical illumination of metal halide perovskites with mixed halides<br/>(bromide and iodide).<br/>In a meta-data study, we analyze over 45 000 solar cell device metrics to explore the contribution of phase segregation to device<br/>performance.<br/>Furthermore, we analyze the mechanism of phase segregation. In this work, we present insights from photoluminescence mi-<br/>croscopy as well as multimodal photoluminescence and X-ray diffraction measurements of the temperature and composition<br/>dependence of phase segregation. We revealed the complexity of the phase segregation process and proposed an alternative kinetic<br/>model to rationalize the entire process.<br/>In addition, we described the X-ray sensitivity of mixed metal halide perovskites and the challenges encountered when using X-<br/>ray-based characterization techniques. In particular, we discovered that X-ray induced defects can alter the photo-stability of metal<br/>halide perovskites, making meaningful characterization of the phase segregation process very complex.<br/>Our results highlight the complex interplay between ion mobility, photostability, and photon-induced defects. We are confident<br/>that these insights will contribute to a detailed understanding of light-induced phase segregation and ion migration in general. We<br/>hope that this understanding will point the way to stable and reliable operation of metal halide perovskite solar cells.}},
author = {{Suchan, Klara}},
isbn = {{978-91-7422-948-6}},
keywords = {{phase segregation; X-ray diffraction; perovskite; solar cells; photoluminescence}},
language = {{eng}},
publisher = {{Lund University}},
school = {{Lund University}},
title = {{Life and Death of Mixed Metal Halide Perovskites : Mechanism and Consequences of Light Induced Halide Segregation in MAPb(I,Br)3}},
url = {{https://lup.lub.lu.se/search/files/144068508/Klara_Suchan_Thesis.pdf}},
year = {{2023}},
}