Saved in:
Bibliographic Details
Main Authors: Cohn, Rachael L., Petroff, Christopher A., McGhee, Virginia E., Marohn, John A.
Format: Preprint
Published: 2024
Subjects:
Online Access:https://arxiv.org/abs/2402.15501
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866913241642303488
author Cohn, Rachael L.
Petroff, Christopher A.
McGhee, Virginia E.
Marohn, John A.
author_facet Cohn, Rachael L.
Petroff, Christopher A.
McGhee, Virginia E.
Marohn, John A.
contents We used broadband local dielectric spectroscopy (BLDS), an electric force microscopy technique, to make non-contact measurements of conductivity in the dark and under illumination of PM6:Y6 and Y6 prepared on ITO and PEDOT:PSS/ITO. Over a range of illumination intensities, BLDS spectra were acquired and fit to an impedance model of the tip-sample interaction to obtain a sample resistance and capacitance. By comparing two descriptions of cantilever friction, an impedance model and a microscopic model, we connected the sample resistance inferred from impedance modeling to a microscopic sample conductivity. A charge recombination rate was estimated from plots of the conductivity versus light intensity and found to be sub-Langevin. The dark conductivity was orders of magnitude higher than expected from Fermi-level equilibration of the PM6:Y6 with the substrate, suggesting that dark carriers may be a source of open-circuit voltage loss in PM6:Y6.
format Preprint
id arxiv_https___arxiv_org_abs_2402_15501
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Electrical Scanning Probe Microscope Measurements Reveal Surprisingly High Dark Conductivity in Y6 and PM6:Y6 and Non-Langevin Recombination in PM6:Y6
Cohn, Rachael L.
Petroff, Christopher A.
McGhee, Virginia E.
Marohn, John A.
Materials Science
Applied Physics
We used broadband local dielectric spectroscopy (BLDS), an electric force microscopy technique, to make non-contact measurements of conductivity in the dark and under illumination of PM6:Y6 and Y6 prepared on ITO and PEDOT:PSS/ITO. Over a range of illumination intensities, BLDS spectra were acquired and fit to an impedance model of the tip-sample interaction to obtain a sample resistance and capacitance. By comparing two descriptions of cantilever friction, an impedance model and a microscopic model, we connected the sample resistance inferred from impedance modeling to a microscopic sample conductivity. A charge recombination rate was estimated from plots of the conductivity versus light intensity and found to be sub-Langevin. The dark conductivity was orders of magnitude higher than expected from Fermi-level equilibration of the PM6:Y6 with the substrate, suggesting that dark carriers may be a source of open-circuit voltage loss in PM6:Y6.
title Electrical Scanning Probe Microscope Measurements Reveal Surprisingly High Dark Conductivity in Y6 and PM6:Y6 and Non-Langevin Recombination in PM6:Y6
topic Materials Science
Applied Physics
url https://arxiv.org/abs/2402.15501