TY - JOUR
T1 - Transparent and flexible organic semiconductor nanofilms with enhanced thermoelectric efficiency
AU - Lee, Seung Hwan
AU - Park, Hongkwan
AU - Kim, Soyeon
AU - Son, Woohyun
AU - Cheong, In Woo
AU - Kim, Jung Hyun
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 2014/5/28
Y1 - 2014/5/28
N2 - Sequential doping and dedoping increased the conductivity and optimized the oxidation level of transparent and flexible poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonic acid) (PEDOT:PSS) films, resulting in an improvement in the thermoelectric figure of merit ZT. The electrical conductivity (σ) increased from 970 to 1260 S cm-1 and the power factor from 66.5 to 70.7 μW mK-2 at the optimum concentration of the chemical dopant p-toluenesulfonic acid monohydrate (TSA). Then, the doped PEDOT:PSS films were treated with hydrazine/DMSO solutions with different hydrazine concentrations to precisely control the oxidation level. During the hydrazine/DMSO treatment (dedoping), σ of the films continuously decreased from 1647 to 783 S cm-1 due to a decrease in the carrier concentration, whereas the Seebeck coefficient (S) steeply increased from 28 to 49.3 μV K-1 at the optimum oxidation level. A power factor of 318.4 μW mK-2 (σ = 1310 S cm-1, S = 49.3 μV K-1), the highest among all existing thermoelectric nanofilms, was achieved while maintaining polymer film flexibility and transparency (88.3% of optical transmittance). In addition, the thermal conductivity (κ) of the PEDOT:PSS films decreased from 0.38 to 0.30 W mK-1 upon removal of PSS. At the lowest κ value, a high ZT value of 0.31 was achieved at room temperature.
AB - Sequential doping and dedoping increased the conductivity and optimized the oxidation level of transparent and flexible poly(3,4-ethylenedioxythiophene): poly(4-styrene sulfonic acid) (PEDOT:PSS) films, resulting in an improvement in the thermoelectric figure of merit ZT. The electrical conductivity (σ) increased from 970 to 1260 S cm-1 and the power factor from 66.5 to 70.7 μW mK-2 at the optimum concentration of the chemical dopant p-toluenesulfonic acid monohydrate (TSA). Then, the doped PEDOT:PSS films were treated with hydrazine/DMSO solutions with different hydrazine concentrations to precisely control the oxidation level. During the hydrazine/DMSO treatment (dedoping), σ of the films continuously decreased from 1647 to 783 S cm-1 due to a decrease in the carrier concentration, whereas the Seebeck coefficient (S) steeply increased from 28 to 49.3 μV K-1 at the optimum oxidation level. A power factor of 318.4 μW mK-2 (σ = 1310 S cm-1, S = 49.3 μV K-1), the highest among all existing thermoelectric nanofilms, was achieved while maintaining polymer film flexibility and transparency (88.3% of optical transmittance). In addition, the thermal conductivity (κ) of the PEDOT:PSS films decreased from 0.38 to 0.30 W mK-1 upon removal of PSS. At the lowest κ value, a high ZT value of 0.31 was achieved at room temperature.
UR - http://www.scopus.com/inward/record.url?scp=84899416723&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84899416723&partnerID=8YFLogxK
U2 - 10.1039/c4ta00700j
DO - 10.1039/c4ta00700j
M3 - Article
AN - SCOPUS:84899416723
VL - 2
SP - 7288
EP - 7294
JO - Journal of Materials Chemistry A
JF - Journal of Materials Chemistry A
SN - 2050-7488
IS - 20
ER -