The photothermoelectric (PTE) effect in conductive polymers is significant because it combines high photothermal (PT) and thermoelectric (TE) effects. Using poly(3,4-ethylenedioxythiophene) (PEDOT) films with various conductivities and crystallinities, the PTE effect in thin films can be established. The PT temperature increase (ΔT PT ) under light exposure and the thermal voltage induced by ΔT PT for a series of PEDOT films indicated an unparalleled sensitivity to the carrier mobility in PT and TE conversions. The PTE Seebeck coefficients (S PTE ) and power factors (PF PTE ) for the PEDOT films correlated well with those in the dark state, indicating that the PTE effect in PEDOT can be translated into the TE effect induced by heating upon light exposure. The 180 nm-thick pristine PEDOT film shows high PF PTE values of 620 and 590 μW m -1 K -2 for a near-infrared laser and sunlight, respectively. The thin-film solar TE harvester with four PEDOT legs generates a power density of 38 mW m -2 and an energy density of 420 W h g -1 , demonstrating the first and highest absorber-free organic solar TE output yet reported. Thus, the PT conversion mechanisms in CP films can be extended to thin-film solar energy harvesters.
Bibliographical noteFunding Information:
This research was supported by a National Research Foundation (NRF) grant funded by the Korean government (Ministry of Science, ICT & Future Planning, MSIP) through the Global Research Lab (2016K1A1A2912753), Brain Pool program (2018H1D3A2001751), Creative Materials Discovery Program (2018M3D1A1058536), and a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI15C0942). This work was supported (in part) by the Yonsei University Research Fund (Post Doc. Researcher Supporting Program) of 2016 (project no. 2016-12-0015).
© 2019 The Royal Society of Chemistry.
All Science Journal Classification (ASJC) codes
- Renewable Energy, Sustainability and the Environment
- Materials Science(all)