Smith Phil M, Su Laisuo, Gong Wei, Nakamura Nathan, Reeja-Jayan B, Shen Sheng
Department of Mechanical Engineering, Carnegie Mellon University Pittsburgh PA 15213 USA
RSC Adv. 2018 May 25;8(35):19348-19352. doi: 10.1039/c8ra03302a.
Oxidative chemical vapor deposition (oCVD) is a versatile technique that can simultaneously tailor properties (, electrical, thermal conductivity) and morphology of polymer films at the nanoscale. In this work, we report the thermal conductivity of nanoscale oCVD grown poly(3,4-ethylenedioxythiophene) (PEDOT) films for the first time. Measurements as low as 0.16 W m K are obtained at room temperature for PEDOT films with thicknesses ranging from 50-100 nm. These values are lower than those for solution processed PEDOT films doped with the solubilizing agent PSS (polystyrene sulfonate). The thermal conductivity of oCVD grown PEDOT films show no clear dependence on electrical conductivity, which ranges from 1 S cm to 30 S cm. It is suspected that at these electrical conductivities, the electronic contribution to the thermal conductivity is extremely small and that phonon transport is dominant. Our findings suggest that CVD polymerization is a promising route towards engineering polymer films that combine low thermal conductivity with relatively high electrical conductivity values.
氧化化学气相沉积（oCVD）是一种通用技术，能够在纳米尺度上同时调整聚合物薄膜的性质（如电学、热导率）和形态。在本工作中，我们首次报道了纳米尺度oCVD生长的聚（3,4-亚乙基二氧噻吩）（PEDOT）薄膜的热导率。对于厚度在50 - 100纳米范围内的PEDOT薄膜，在室温下测得的热导率低至0.16 W m⁻¹ K⁻¹。这些值低于掺杂有增溶剂聚苯乙烯磺酸盐（PSS）的溶液法制备的PEDOT薄膜的值。oCVD生长的PEDOT薄膜的热导率对电导率没有明显依赖性，电导率范围为1 S cm⁻¹至30 S cm⁻¹。据推测，在这些电导率下，电子对热导率的贡献极小，声子传输占主导。我们的研究结果表明，化学气相沉积聚合是制备兼具低热导率和相对高电导率的聚合物薄膜的一条有前景的途径。
