Charge Carrier Dynamics of Lead Halide Perovskites Probed with Ultrafast Spectroscopy

In this thesis, we investigate the nature of charge carrier generation, relaxation and recombination in a range of lead halide perovskites. We focus on understanding whether the photophysical behaviour of these perovskite materials is like that of highly-ordered inorganic crystalline semiconductors (exhibiting ballistic charge transport) or disordered molecular semiconductors (exhibiting strong electron-phonon coupling and highly localised excited states) and how we can tune these photophysical properties with inorganic and organic additives. We find that the fundamental photophysical properties of lead halide perovskites, such as charge carrier relaxation and recombination, arise from the lead halide lattice rather than the choice of A-site cation. We show that while the choice of A-site cation does not affect these photophysical properties directly, it can have a significant impact on the structure of the lead halide lattice and therefore affect these photophysical properties indirectly. We demonstrate that lead halide perovskites fabricated from particular inorganic and organic A-site cation combinations exhibit low parasitic trap densities and enhanced carrier interactions. Furthering our understanding of how the photophysical properties of these materials can be controlled through chemical composition is extremely important for the future design of highly efficient solar cells and light emitting diodes.

Name dc:type.qualificationname

Doctor of Philosophy (PhD)

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

University of Cambridge

Year dc:date.issued

2018

Author dc:creator

• Rivett, Jasmine Pamela Helen

Advisors dc:contributor.advisor

• Credgington, Dan
• Deschler, Felix
• Cheetham, Anthony

• Lead halide perovskite
• Ultrafast spectroscopy
• Semiconductor
• Perovskite
• Laser spectroscopy
• Femtosecond spectroscopy
• Charge carrier relaxation
• Polarisation anisotropy
• Pump-probe
• Transient absorption

Licence

• https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/9d81731d-56e2-4506-93fb-df96f09d69b8/download
• https://www.rioxx.net/licenses/all-rights-reserved/

Language dc:language

en

DOI dc:identifier.doi

https://doi.org/10.17863/CAM.22275

OAI identifier oai:identifier

oai:www.repository.cam.ac.uk:1810/275095