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Acidity-Controlled Conducting Polymer Films for Organic Thermoelectric Devices with Horizontal and Vertical Architectures

View Article: PubMed Central - PubMed

ABSTRACT

Organic thermoelectric devices (OTEDs) are recognized one of the next generation energy conversion platforms because of their huge potentials for securing electricity continuously from even tiny heat sources in our daily life. The advantage of OTEDs can be attributable to the design freedom in device shapes and the low-cost fabrication by employing solution coating processes at low temperatures. As one of the major OTE materials to date, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has been used, but no study has been yet carried out on its acidity control even though the acidic components in OTEDs can seriously affect the device performance upon operation. Here we demonstrate that the addition of aniline (a weak base) can control the acidity of PEDOT:PSS and enhance the performance of OTEDs. In particular, the vertical OTEDs with aniline-doped PEDOT:PSS films (active area = 1.0 cm2) could continuously generate electricity (0.06 nW) even at low temperatures (<38 °C) when they were mounted on a desk lamp (power = 24 W).

No MeSH data available.


(a) Comparison of thermoelectric (TE) characteristics (voltage, current, power, and Seebeck coefficient (S)) between horizontal (H-OTED) and vertical (V-OTED) devices with the 230 μm-thick PEDOT:PSS_ANL films (RA/P = 1.5) as a function of temperature difference.(b) TE characteristics between the two OTEDs (H-OTED and V-OTED) at ΔT = 50 K.
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f5: (a) Comparison of thermoelectric (TE) characteristics (voltage, current, power, and Seebeck coefficient (S)) between horizontal (H-OTED) and vertical (V-OTED) devices with the 230 μm-thick PEDOT:PSS_ANL films (RA/P = 1.5) as a function of temperature difference.(b) TE characteristics between the two OTEDs (H-OTED and V-OTED) at ΔT = 50 K.

Mentions: The thick (230 μm) PEDOT:PSS_ANL films were employed for the fabrication of the OTEDs with the vertical geometry as discussed in Fig. 1e. The planar OTEDs were also fabricated at the same time for exact comparison. As shown in Fig. 5a, the device voltage was almost linearly increased with temperature irrespective of the device geometry. However, the vertical OTED showed higher voltage than the planar OTED over the whole temperature range tested in this work. In particular, the voltage difference between the two OTEDs became much greater at higher temperatures. Similarly, the device current was also increased with temperature but the current gap between the two OTEDs became much more pronounced as the temperature increased. The vertical OTED generated −189.5 μA at ΔT = 50 °C, which is almost 4-fold of the current (−43.30 μA) generated in the planar OTED (see Fig. 5b). As a result, the vertical OTED could produce higher electrical power than the planar OTED. The outstanding performance of the vertical OTED is also supported by the higher Seebeck coefficient that reached 21.37 μV/K for the vertical OTED compared to 13.04 μV/K for the planar OTED at ΔT = 50 °C. The TE parameters are summarized in Table S3, in which the influence of coating method on the device performance is given for the OTEDs with the thin (70 nm) PEDOT:PSS_ANL films for reference.


Acidity-Controlled Conducting Polymer Films for Organic Thermoelectric Devices with Horizontal and Vertical Architectures
(a) Comparison of thermoelectric (TE) characteristics (voltage, current, power, and Seebeck coefficient (S)) between horizontal (H-OTED) and vertical (V-OTED) devices with the 230 μm-thick PEDOT:PSS_ANL films (RA/P = 1.5) as a function of temperature difference.(b) TE characteristics between the two OTEDs (H-OTED and V-OTED) at ΔT = 50 K.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5035924&req=5

f5: (a) Comparison of thermoelectric (TE) characteristics (voltage, current, power, and Seebeck coefficient (S)) between horizontal (H-OTED) and vertical (V-OTED) devices with the 230 μm-thick PEDOT:PSS_ANL films (RA/P = 1.5) as a function of temperature difference.(b) TE characteristics between the two OTEDs (H-OTED and V-OTED) at ΔT = 50 K.
Mentions: The thick (230 μm) PEDOT:PSS_ANL films were employed for the fabrication of the OTEDs with the vertical geometry as discussed in Fig. 1e. The planar OTEDs were also fabricated at the same time for exact comparison. As shown in Fig. 5a, the device voltage was almost linearly increased with temperature irrespective of the device geometry. However, the vertical OTED showed higher voltage than the planar OTED over the whole temperature range tested in this work. In particular, the voltage difference between the two OTEDs became much greater at higher temperatures. Similarly, the device current was also increased with temperature but the current gap between the two OTEDs became much more pronounced as the temperature increased. The vertical OTED generated −189.5 μA at ΔT = 50 °C, which is almost 4-fold of the current (−43.30 μA) generated in the planar OTED (see Fig. 5b). As a result, the vertical OTED could produce higher electrical power than the planar OTED. The outstanding performance of the vertical OTED is also supported by the higher Seebeck coefficient that reached 21.37 μV/K for the vertical OTED compared to 13.04 μV/K for the planar OTED at ΔT = 50 °C. The TE parameters are summarized in Table S3, in which the influence of coating method on the device performance is given for the OTEDs with the thin (70 nm) PEDOT:PSS_ANL films for reference.

View Article: PubMed Central - PubMed

ABSTRACT

Organic thermoelectric devices (OTEDs) are recognized one of the next generation energy conversion platforms because of their huge potentials for securing electricity continuously from even tiny heat sources in our daily life. The advantage of OTEDs can be attributable to the design freedom in device shapes and the low-cost fabrication by employing solution coating processes at low temperatures. As one of the major OTE materials to date, poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) has been used, but no study has been yet carried out on its acidity control even though the acidic components in OTEDs can seriously affect the device performance upon operation. Here we demonstrate that the addition of aniline (a weak base) can control the acidity of PEDOT:PSS and enhance the performance of OTEDs. In particular, the vertical OTEDs with aniline-doped PEDOT:PSS films (active area = 1.0 cm2) could continuously generate electricity (0.06 nW) even at low temperatures (<38 °C) when they were mounted on a desk lamp (power = 24 W).

No MeSH data available.