Electrical conductivity of plasma‐treated poly(p‐phenylene sulfide) doped with iodine

Abstract

AbstractPlasma treatment of poly(p‐phenylene sulfide) (PPS) doped with I2 is found to increase both the electrical conductivity and the stability of the material. The average conductivity of plasma‐treated samples reaches an apparently saturated value of 1.7 × 10−3s cm−1, which is about six orders of magnitude higher than that of the same material without plasma treatment, and this conductivity remains practically unchanged under exposure to ambient environment for 10 days. Infrared and secondary ion mass spectra of the samples before and after plasma treatment suggest that the charge‐transfer complexes are formed in PPS doped with I2 after plasma treatment. This is also consistent with the temperature dependence of conductivity results which show that the activation energy for electrical conduction decreases from 2.0 eV for pure PPS to 0.2 eV for plasma‐treated I2‐doped PPS. Using isothermal potential and current decay techniques, we have also measured the trap density distribution. Plasma treatment, on the one hand, does create more traps in PPS, but, on the other hand, it enhances conductivity. The mechanism of electrical conduction is briefly discussed.