Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields

Ari Ivaska, Jan-Erik Österholm, Pentti Passiniemi, Pekka Kuivalainen, Heikki Isotalo, Henrik Stubb

Research output: Contribution to journalArticleScientific

3 Citations (Scopus)

Abstract

We have studied the effect of a strong d.c. field on the i.r. absorbance bands of lightly FeCl4−-doped polythiophene (PT) thin films. The electrochemically prepared PT-BF4− films were first electrochemically reduced and then chemically doped with FeCl3. The d.c. conductivities of the films were in the range 10−6-10−4ω−1cm−1. Application of a d.c. electric field < 4 kV/cm caused large changes in the absorbances of the i.r. modes, especially in the CH stretching, CH in- and out-of-plane vibrational modes and in the bands corresponding to the thiophene ring stretching. Also the absorbances of the doping-induced bands changed substantially, but they relaxed close to the original values faster than the other modes after the field was switched off. Special care was taken to study the contribution of heating of the film to the observed results by measuring the temperature of the films both by using a thermocouple and by using the films itself as a sensitive temperature sensor. Various mechanisms including, e.g., structural changes in the disordered PT material, charge injection-induced polaron or bipolaron formation and doping continuation may contribute to the observed large changes in the i.r. modes of PT.
Original languageEnglish
Pages (from-to)215-221
JournalSynthetic Metals
Volume21
Issue number1-3
DOIs
Publication statusPublished - 1987
MoE publication typeB1 Article in a scientific magazine
EventConference on Electronic Processes in Conducting Polymers - Vadstena, Sweden
Duration: 18 Aug 198620 Aug 1986

Fingerprint

Fourier transforms
Electric fields
Infrared radiation
electric fields
Polymers
Stretching
Doping (additives)
methylidyne
Thiophenes
Gene Conversion
Charge injection
temperature sensors
Thiophene
Temperature sensors
thermocouples
Thermocouples
thiophenes
vibration mode
polythiophene
injection

Cite this

Ivaska, A., Österholm, J-E., Passiniemi, P., Kuivalainen, P., Isotalo, H., & Stubb, H. (1987). Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields. Synthetic Metals, 21(1-3), 215-221. https://doi.org/10.1016/0379-6779(87)90089-0
Ivaska, Ari ; Österholm, Jan-Erik ; Passiniemi, Pentti ; Kuivalainen, Pekka ; Isotalo, Heikki ; Stubb, Henrik. / Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields. In: Synthetic Metals. 1987 ; Vol. 21, No. 1-3. pp. 215-221.
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title = "Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields",
abstract = "We have studied the effect of a strong d.c. field on the i.r. absorbance bands of lightly FeCl4−-doped polythiophene (PT) thin films. The electrochemically prepared PT-BF4− films were first electrochemically reduced and then chemically doped with FeCl3. The d.c. conductivities of the films were in the range 10−6-10−4ω−1cm−1. Application of a d.c. electric field < 4 kV/cm caused large changes in the absorbances of the i.r. modes, especially in the CH stretching, CH in- and out-of-plane vibrational modes and in the bands corresponding to the thiophene ring stretching. Also the absorbances of the doping-induced bands changed substantially, but they relaxed close to the original values faster than the other modes after the field was switched off. Special care was taken to study the contribution of heating of the film to the observed results by measuring the temperature of the films both by using a thermocouple and by using the films itself as a sensitive temperature sensor. Various mechanisms including, e.g., structural changes in the disordered PT material, charge injection-induced polaron or bipolaron formation and doping continuation may contribute to the observed large changes in the i.r. modes of PT.",
author = "Ari Ivaska and Jan-Erik {\"O}sterholm and Pentti Passiniemi and Pekka Kuivalainen and Heikki Isotalo and Henrik Stubb",
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Ivaska, A, Österholm, J-E, Passiniemi, P, Kuivalainen, P, Isotalo, H & Stubb, H 1987, 'Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields', Synthetic Metals, vol. 21, no. 1-3, pp. 215-221. https://doi.org/10.1016/0379-6779(87)90089-0

Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields. / Ivaska, Ari; Österholm, Jan-Erik; Passiniemi, Pentti; Kuivalainen, Pekka; Isotalo, Heikki; Stubb, Henrik.

In: Synthetic Metals, Vol. 21, No. 1-3, 1987, p. 215-221.

Research output: Contribution to journalArticleScientific

TY - JOUR

T1 - Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields

AU - Ivaska, Ari

AU - Österholm, Jan-Erik

AU - Passiniemi, Pentti

AU - Kuivalainen, Pekka

AU - Isotalo, Heikki

AU - Stubb, Henrik

PY - 1987

Y1 - 1987

N2 - We have studied the effect of a strong d.c. field on the i.r. absorbance bands of lightly FeCl4−-doped polythiophene (PT) thin films. The electrochemically prepared PT-BF4− films were first electrochemically reduced and then chemically doped with FeCl3. The d.c. conductivities of the films were in the range 10−6-10−4ω−1cm−1. Application of a d.c. electric field < 4 kV/cm caused large changes in the absorbances of the i.r. modes, especially in the CH stretching, CH in- and out-of-plane vibrational modes and in the bands corresponding to the thiophene ring stretching. Also the absorbances of the doping-induced bands changed substantially, but they relaxed close to the original values faster than the other modes after the field was switched off. Special care was taken to study the contribution of heating of the film to the observed results by measuring the temperature of the films both by using a thermocouple and by using the films itself as a sensitive temperature sensor. Various mechanisms including, e.g., structural changes in the disordered PT material, charge injection-induced polaron or bipolaron formation and doping continuation may contribute to the observed large changes in the i.r. modes of PT.

AB - We have studied the effect of a strong d.c. field on the i.r. absorbance bands of lightly FeCl4−-doped polythiophene (PT) thin films. The electrochemically prepared PT-BF4− films were first electrochemically reduced and then chemically doped with FeCl3. The d.c. conductivities of the films were in the range 10−6-10−4ω−1cm−1. Application of a d.c. electric field < 4 kV/cm caused large changes in the absorbances of the i.r. modes, especially in the CH stretching, CH in- and out-of-plane vibrational modes and in the bands corresponding to the thiophene ring stretching. Also the absorbances of the doping-induced bands changed substantially, but they relaxed close to the original values faster than the other modes after the field was switched off. Special care was taken to study the contribution of heating of the film to the observed results by measuring the temperature of the films both by using a thermocouple and by using the films itself as a sensitive temperature sensor. Various mechanisms including, e.g., structural changes in the disordered PT material, charge injection-induced polaron or bipolaron formation and doping continuation may contribute to the observed large changes in the i.r. modes of PT.

U2 - 10.1016/0379-6779(87)90089-0

DO - 10.1016/0379-6779(87)90089-0

M3 - Article

VL - 21

SP - 215

EP - 221

JO - Synthetic Metals

JF - Synthetic Metals

SN - 0379-6779

IS - 1-3

ER -

Ivaska A, Österholm J-E, Passiniemi P, Kuivalainen P, Isotalo H, Stubb H. Fourier transform infrared study of lightly doped polythiophene under d.c. electric fields. Synthetic Metals. 1987;21(1-3):215-221. https://doi.org/10.1016/0379-6779(87)90089-0