Terahertz complex conductivities of carriers with partial localization in doped polythiophenes

Unuma, Takeya; Fujii, Kenji; Kishida, Hideo; Nakamura, Arao
July 2010
Applied Physics Letters;7/19/2010, Vol. 97 Issue 3, p033308
Academic Journal
We have investigated the complex conductivity spectra σ(ω) of two p-doped polythiophenes—poly(3-hexylthiophene) and poly(3,4-ethylenedioxythiophene)—with various carrier densities by using terahertz time-domain spectroscopy. The real part of σ(ω) is found to gradually decrease with decreasing frequency ω and to approach a finite value for ω→0 unlike the Drude conductivity behavior, suggesting that carriers in polythiophenes have a partially localized nature. By reproducing both the measured real and imaginary parts of σ(ω) with the Drude–Smith model, we show that carriers become less localized with increasing carrier density up to ∼1.8×1020 cm-3.


Related Articles

  • Terahertz electrical and optical characteristics of double-walled carbon nanotubes and their comparison with single-walled carbon nanotubes. Maeng, Inhee; Kang, Chul; Oh, Seung Jae; Son, Joo-Hiuk; An, Kay Hyeok; Lee, Young Hee // Applied Physics Letters;1/29/2007, Vol. 90 Issue 5, p051914 

    The electrical and optical properties of double-walled carbon nanotubes (DWNTs) have been characterized and compared with those of single-walled carbon nanotubes (SWNTs) utilizing terahertz time-domain spectroscopy. The power absorption and the complex refractive indices of DWNTs are smaller...

  • Spatially resolved doping concentration measurement in semiconductors via spin noise spectroscopy. Römer, M.; Hübner, J.; Oestreich, M. // Applied Physics Letters;3/16/2009, Vol. 94 Issue 11, p112105 

    We propose and demonstrate spin noise spectroscopy as an efficient, noncontact method to measure doping concentrations in semiconductors with high accuracy and high spatial resolution. In a proof of concept study, two different doping levels in a silicon-doped GaAs stack are depth resolved with...

  • Regular pulsing induced by noise in a monolithic semiconductor neuron. Samardak, Alexander S.; Nogaret, Alain; Taylor, Stephen; Janson, Natalia B.; Balanov, Alexander G.; Farrer, Ian; Ritchie, David A. // AIP Conference Proceedings;1/4/2010, Vol. 1199 Issue 1, p523 

    We report on the stochastic dynamics of a semiconductor neuron that uses the non-linear conductances of modulation doped semiconductors to compute electrical spikes. This GaAs-based neuron has pn wires which propagate and delay electrical pulses and a soma which sums and regenerates pulses...

  • Spectroscopic study of V doped Hg0.018Cd0.981Mn0.001Te bulk crystals as near-infrared materials for optical applications. Gnatenko, Yu. P.; Bukivskij, P. M.; Piryatinski, Yu. P.; Faryna, I. O.; Shigiltchoff, O. A.; Gamernyk, R. V. // Applied Physics Letters;9/14/2009, Vol. 95 Issue 11, p112109 

    It was shown that the photosensitivity region of the semi-insulating V doped Hg0.018Cd0.981Mn0.001Te crystals extends up to 1800 nm and is caused by the electron photogeneration resulting in the transitions from the main 4T1(F) state to the excited 4A2(F)- and 4T1(P) states of V2+ ions, which...

  • On the superlinear increase in conductivity with dopant concentration in excitonic semiconductors. Gregg, Brian A.; Chen, Si-Guang; Branz, Howard M. // Applied Physics Letters;3/8/2004, Vol. 84 Issue 10, p1707 

    We show that the same factors that cause exciton formation in organic (excitonic) semiconductors, the low dielectric constant and the localized wave functions of the charge carriers, also control their doping processes. We compare doping in organic and inorganic semiconductors and show that the...

  • Fractional ac Josephson effect in unconventional superconductors. Kwon, H. -J.; Yakovenko, V. M.; Sengupta, K. // Low Temperature Physics;Jul/Aug2004, Vol. 30 Issue 7/8, p613 

    For certain orientations of Josephson junctions between two px-wave or two d-wave superconductors, the subgap Andreev bound states produce a 4π-periodic relation between the Josephson current I and the phase difference φ: I∝sin(φ/2). Consequently, the ac Josephson current has...

  • AC electric conductivity of MnGa2S4 single crystals. Niftiev, N. N.; Tagiev, O. B.; Muradov, M. B.; Mamedov, F. M.; Kazymova, F. A. // Technical Physics Letters;Nov2009, Vol. 35 Issue 11, p1062 

    The frequency spectra and temperature dependences of the ac electric conductivity of MnGa2S4 single crystals have been studied. It is established that the conductivity increases with the frequency and exhibits a resonance at 435–500 kHz. The activation energies of current carriers are...

  • How much charge is there on a pulsating Taylor cone? Marginean, Ioan; Nemes, Peter; Parvin, Lida; Vertes, Akos // Applied Physics Letters;8/7/2006, Vol. 89 Issue 6, p064104 

    The authors show that the capillary wave frequency spectrum of a charged droplet also gives an accurate estimate for the Taylor cone [Proc. R. Soc. London A 280, 383 (1964)] pulsation frequency. For low conductivity liquids and relatively large radius emitters, this frequency is mainly...

  • Direct observation of carrier delocalization in highly conducting polyaniline. Unuma, Takeya; Yamada, Naruki; Nakamura, Arao; Kishida, Hideo; Lee, Seung-Chul; Hong, Eun-Young; Lee, Suck-Hyun; Kwon, O-Pil // Applied Physics Letters;7/29/2013, Vol. 103 Issue 5, p053303 

    We investigate the complex conductivity spectra σ(ω) of doped polyaniline, prepared as a typical conjugated polymer with various dc electrical conductivities up to 1000 S/cm, by using terahertz transmission spectroscopy. With the increase in dc conductivity, the imaginary part of...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics