Inhomogeneous Doping of Polyaniline Doped with Sodium-Hexafluorophosphate (NaPF6)
Inhomogeneous Doping of Polyaniline Doped with Sodium-Hexafluorophosphate (NaPF6)
- 주제(키워드) Polyaniline , Conductivity , Doping , Thermoelectric power
- 발행기관 한국물리학회
- 발행년도 2002
- 총서유형 Journal
- UCI G704-000411.2002.40.5.031
- KCI ID ART000881943
- 본문언어 영어
초록/요약
We report the charge transport properties of a polyaniline (PAN) sample doped with NaPF6 (PAN-NaPF6) by using the temperature dependent dc conductivity ( dc) and thermoelectric power, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR) experiments. The dc of the system is 0.8 S/cm at room temperature, and its temperature dependence follows a quasi one-dimensional (1D) variable range hopping (VRH) model. The thermoelectric power at room temperature is positive, implying hole transport in the system, and its temperature dependence is interpreted in terms of the metallic nature at high temperatures ( 150 K) and the quasi 1D VRH characteristics at low temperatures ( 150 K). The doping concentration of the sample is obtained from XPS experiments. The density of states of the PAN-NaPF6 sample is estimated to be 1.18 st./(eV 2 rings), which is lower than that of conventional hydrochloric-acid-doped PAN (PAN-ES) samples. We compare the doping mechanism of PAN-NaPF6 with that of PAN-ES based on the results of EPR and XPS argon-ion sputtering experiments. We observe that Na+ and counter ions mainly exist near the surface of the PAN-NaPF6 sample and are inhomogeneously distributed through the sample.
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