TY - JOUR
T1 - Band transport evidence in PEDOT:PSS films using broadband optical spectroscopy from terahertz to ultraviolet region
AU - Guo, Zijing
AU - Sato, Tetsu
AU - Han, Yang
AU - Takamura, Naoki
AU - Ikeda, Ryohei
AU - Miyamoto, Tatsuya
AU - Kida, Noriaki
AU - Ogino, Makiko
AU - Takahashi, Youtarou
AU - Kasuya, Naotaka
AU - Watanabe, Shun
AU - Takeya, Jun
AU - Wei, Qingshuo
AU - Mukaida, Masakazu
AU - Okamoto, Hiroshi
N1 - Publisher Copyright:
© The Author(s) 2024.
PY - 2024/12
Y1 - 2024/12
N2 - Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is a prototypical conducting polymer. When a polar solvent is used during film fabrication, the hole-doped PEDOT oligomers form crystalline clusters in the films, exhibiting high conductivity. However, whether hole carriers exhibit band transport has not been clarified yet. Here, we employ a multilayer spin-coating method using an aqueous solution with ethylene glycol, with additional procedures of dipping the films in ethylene glycol or dropping sulfuric acid onto the films, to achieve a high DC conductivity of ∼1000 S cm−1 or higher. Using terahertz time-domain spectroscopy and far-infrared-to-ultraviolet reflection spectroscopy, we derive complex optical conductivity σ̃ spectra, which are reproduced by the sum of the Drude response, and Lorentz-oscillator responses due to phonons. These results demonstrate the band transport, which is further confirmed by the Hall effect measurements. The hole mobility estimated from the spectral analyses is 7–11 cm2 V−1 s−1, a significantly large value. The reported evaluation methods for broadband σ̃ spectra can help elucidate carrier transport mechanisms in various conducting films.
AB - Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is a prototypical conducting polymer. When a polar solvent is used during film fabrication, the hole-doped PEDOT oligomers form crystalline clusters in the films, exhibiting high conductivity. However, whether hole carriers exhibit band transport has not been clarified yet. Here, we employ a multilayer spin-coating method using an aqueous solution with ethylene glycol, with additional procedures of dipping the films in ethylene glycol or dropping sulfuric acid onto the films, to achieve a high DC conductivity of ∼1000 S cm−1 or higher. Using terahertz time-domain spectroscopy and far-infrared-to-ultraviolet reflection spectroscopy, we derive complex optical conductivity σ̃ spectra, which are reproduced by the sum of the Drude response, and Lorentz-oscillator responses due to phonons. These results demonstrate the band transport, which is further confirmed by the Hall effect measurements. The hole mobility estimated from the spectral analyses is 7–11 cm2 V−1 s−1, a significantly large value. The reported evaluation methods for broadband σ̃ spectra can help elucidate carrier transport mechanisms in various conducting films.
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U2 - 10.1038/s43246-024-00451-1
DO - 10.1038/s43246-024-00451-1
M3 - Article
AN - SCOPUS:85187111806
SN - 2662-4443
VL - 5
JO - Communications Materials
JF - Communications Materials
IS - 1
M1 - 26
ER -