Delocalization and insulator to metal transition in PEDOT:PSS

Mohan, A and Menon, R (2022) Delocalization and insulator to metal transition in PEDOT:PSS. In: Journal of Physics Condensed Matter, 34 (50).

PDF Jou_phy_con_34-50_2022.pdf - Published Version Restricted to Registered users only Download (2MB) | Request a copy

Abstract

Charge transport in poly(3,4-ethylenedioxythiophene):poly(styrene-sulfonate) (PEDOT:PSS), with systematic increase in the percentages of dimethyl sulfoxide (DMSO) and ethylene glycol (EG), is investigated as a function of temperature and electric field down to 4.2 K. The conductivity in pristine PEDOT:PSS (1.4 S cm−1) increased to 1070 S cm−1 with 10% of DMSO, and to 565 S cm−1 with 6% of EG. The conductivity ratio ( σ r = σ 300K / σ 4 .2K ) is substantially reduced to 2.5 in 10% DMSO sample. This gradual transition from insulator (variable range hopping) to disordered metal (T 1/2 fit), with an intermediate critical regime (power law), is observed by small variations in the volume fractions of these solvents. The temperature dependence of the ratio of hopping length to localization length ( R / L c ) is rather weak for samples (2D & 4EG) near the transition. As the delocalization increases in more conducting samples, larger electric field dependence of conductivity is observed at lower fields (0.1 V cm−1). The real part of impedance decreases at higher frequency and the peak in the imaginary part of impedance shifts to higher frequency as the sample conductivity increases.

Item Type:	Journal Article
Publication:	Journal of Physics Condensed Matter
Publisher:	Institute of Physics
Additional Information:	The copyright for this article belongs to Institute of Physics.
Keywords:	Dimethyl sulfoxide; Electric fields; Ethylene; Ethylene glycol; Metal insulator boundaries; Metal insulator transition; Organic solvents; Styrene; Temperature distribution, Conductivity ratio; Delocalizations; Ethylenedioxythiophenes; Gradual transition; High frequency HF; Insulator-to-metal transitions; Metal-insulators transitions; Poly(3,4-ethylenedioxythiophene):poly(styrene-sulphonate); Poly(styrene sulfonate); Variable-range hopping, Conducting polymers
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	29 Dec 2022 10:47
Last Modified:	29 Dec 2022 10:47
URI:	https://eprints.iisc.ac.in/id/eprint/78617

Actions (login required)

View Item