Drift in the resistance of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) printed films during thermal cycling

We report on the investigation of the suitability of printed poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films for temperature sensing devices. Gravure printing with the advantage of low cost production was used to prepare thin films of PEDOT:PSS on a flexible foil substrate. The electrical resistance was studied during thermal cycling and exposure to elevated constant temperatures. A drift of the resistance which depends on time, temperature and sample makes the usage as simple temperature sensors not possible. However, a closer look on the drift of relative resistances reveals that integrated temperature-time-profiles can be measured, which might be interesting in connection with monitoring of conditions of storing and transport of sensitive goods.     

聚(3,4-二氧乙撑噻吩)的制备及其热电性能研究

聚(3,4-二氧乙撑噻吩)(PEDOT)以其独特的热稳定性和较高的电导率而引起了广泛关注.首次系统研究了导电PEDOT的热电性能,主要包括电导率、Seebeck系数和热导率,详细比较了化学和电化学方法制备的PEDOT样品在热电性能上的差异.结果表明PEDOT的热电优值最大可以达到1.87×10~(-3)(T=270K),且在相同条件下,PEDOT的热电性能要高出其它有机高分子材料大概一个数量级,而且PEDOT的热电性能依然存在较大的提高潜力.     

Effect of ionic liquid dispersion on performance of a conducting polymer based Schottky diode

The effect of ionic liquid (IL) dispersion on the performance of Schottky diode fabricated with poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has been investigated. Two kinds of ILs including 1-butyl-3-methylimidazolium hexafluorophosphate (BMIPF6, hydrophobic IL) and 1-butyl-3-methylimidazolium chloride (BMICL, hydrophilic IL) were dispersed to the PEDOT:PSS by mechanical stirring and sonication processes. Schottky diodes were fabricated with these mixtures. The forward current of Schottky diodes fabricated with PEDOT:PSS dispersed BMI PF6 (SD-BMIPF6)/BMICL (SD-BMICL) by mechanical stirring is slightly reduced compared with that of Schottky diodes fabricated with pristine PEDOT:PSS (SD-PEDOT). However, SD-BMIPF6 and SD-BMICL by sonication technique show higher forward current with respect to SD-PEDOT. Compared with SD-BMIPF6 and SD-BMICL, the forward current of SD-BMICL is much higher than that of SD-BMIPF6. Since the BMICL has hydrophilic nature, the enhancement of forward current might be due to the uniform dispersion of the BMICL on the PEDOT:PSS matrix.