Spectroscopic investigations of electron and hole dynamics in MAPbBr3 perovskite film and carrier extraction to PEDOT hole transport layer
Autor: | Mojgan Kouhnavard, Pratim Biswas, Julio M. D’Arcy, Yifan Diao, Dariusz M. Niedzwiedzki |
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Rok vydání: | 2021 |
Předmět: |
Materials science
Photoluminescence Absorption spectroscopy Band gap Exciton General Physics and Astronomy 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences Molecular physics 0104 chemical sciences Effective mass (solid-state physics) Ultrafast laser spectroscopy Physical and Theoretical Chemistry 0210 nano-technology Absorption (electromagnetic radiation) Perovskite (structure) |
Zdroj: | Physical Chemistry Chemical Physics. 23:13011-13022 |
ISSN: | 1463-9084 1463-9076 |
DOI: | 10.1039/d1cp00658d |
Popis: | Organometallic halide perovskite (MAPPbBr3), Rust-based Vapor Phase Polymerization (RVPP)-PEDOT hole transporting layers and (RVPP-PEDOT)/MAPPbBr3 dual-layer, deposited on fluorine doped tin oxide glass were studied at room temperature using steady-state absorption, time-resolved photoluminescence imaging and femtosecond time-resolved absorption spectroscopy. Application of these techniques in conjunction with diverse excitation intensities allowed determination of various optoelectronic properties of the perovskite film and the time constant of the hole extraction process. Spectral reconstruction of the bandedge absorption spectrum using Elliot's formula enabled separation of the exciton band. The binding energy of the exciton was determined to be 19 meV and the bandgap energy of the perovskite film was 2.37 eV. Subsequent time-resolved photoluminescence studies of the perovskite film performed using a very weak excitation intensity followed by a global analysis of the data revealed monomolecular recombination dynamics of charge carriers occurring with an amplitude weighted lifetime of 3.2 ns. Femtosecond time-resolved transient absorption of the film performed after excitation intensity spanning a range of over two orders of magnitude enabled determining the rate constant of bimolecular recombination and was found to be 2.6 × 10−10 cm3 s−1. Application of numerous high intensity excitations enabled observation of band filling effect and application of the Burstein–Moss model allowed to determine the reduced effective mass of photoexcited electron–hole pair in MAPPbBr3 film to be 0.19 rest mass of the electron. Finally, application of transient absorption on RVPP-PEDOT/MAPPbBr3 enabled determination of a 0.4 ps time constant for the MAPPbBr3-to-PEDOT hole extraction process. |
Databáze: | OpenAIRE |
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