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  • Spectroscopic investigations of electron and hole dynamics in MAPbBr 3 perovskite film and carrier extraction to PEDOT hole transport layer
Title: Spectroscopic investigations of electron and hole dynamics in MAPbBr 3 perovskite film and carrier extraction to PEDOT hole transport layer
Organometallic halide perovskite (MAPPbBr 3 ), Rust-based Vapor Phase Polymerization (RVPP)-PEDOT hole transporting layers and (RVPP-PEDOT)/MAPPbBr 3 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 cm 3 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 MAPPbBr 3 film to be 0.19 rest mass of the electron. Finally, application of transient absorption on RVPP-PEDOT/MAPPbBr 3 enabled determination of a 0.4 ps time constant for the MAPPbBr 3 -to-PEDOT hole extraction process.  more » « less
Award ID(s):
1806147
PAR ID:
10253123
Author(s) / Creator(s):
; ; ; ;
Date Published:
Journal Name:
Physical Chemistry Chemical Physics
Volume:
23
Issue:
23
ISSN:
1463-9076
Page Range / eLocation ID:
13011 to 13022
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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