Visualizing the impact of chloride addition on the microscopic carrier dynamics of MAPbI3 thin films using femtosecond transient absorption microscopy

The spatial heterogeneity of carrier dynamics in mixed halide perovskite CH3NH3PbI3-xClx thin films with a range of different chloride additions is mapped using femtosecond transient absorption microscopy (TAM). The comparison of TAM images of fibrous and granular polycrystalline CH3NH3PbI3-xClx films indicates that the impact of chloride addition on the local heterogeneity of carrier dynamics is highly dependent on the film preparation method and the resulting morphology. In addition to signals of pristine CH3NH3PbI3, CH3NH3PbI3-xClx films with a fibrous structure show long-lived excited state absorption (ESA) signals in localized, microscopic regions. The ESA signal exhibits transient absorption with a rise time of about 5 ps after the excitation pulse, indicating that these distinct micrograins have preferential carrier trapping properties. The chemical composition of these micrograins does not differ detectably from their surroundings. In contrast, in CH3NH3PbI3-xClx films with a granular structure, Cl addition does not seem to affect the charge carrier dynamics. These results provide insight into the localized effects of halide mixing and on the resulting photophysical properties of mixed halide perovskite materials on the micrometer length scale.

Medienart:

E-Artikel

Erscheinungsjahr:

2019

Erschienen:

2019

Enthalten in:

Zur Gesamtaufnahme - volume:151

Enthalten in:

The Journal of chemical physics - 151(2019), 23 vom: 21. Dez., Seite 234710

Sprache:

Englisch

Beteiligte Personen:

Yu, Jin [VerfasserIn]
Li, Zhongguo [VerfasserIn]
Kolodziej, Charles [VerfasserIn]
Kuyuldar, Seher [VerfasserIn]
Warren, Warren S [VerfasserIn]
Burda, Clemens [VerfasserIn]
Fischer, Martin C [VerfasserIn]

Links:

Volltext

Themen:

Journal Article

Anmerkungen:

Date Completed 30.12.2019

Date Revised 08.01.2020

published: Print

Citation Status PubMed-not-MEDLINE

doi:

10.1063/1.5127875

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM30464711X