Thermoelectrics (TE) are an interesting class of materials which can directly convert heat into electricity or vice versa. Compared with inorganic TE materials, organic polymers have attracted great attention owing to their low thermal conductivity and high TE responses. Whereas the majority of recent reports have explored doping-induced electrical conductivity as the principal parameter for optimizing the characteristics of thermoelectric materials, comparatively fewer studies have investigated the correlation between electrical and thermal transport in organics as well as the inevitable dependence of both on microstructure, doping and degree of orientation [1,2].
ICMAB is one of the main body of the constructs of HORATES to conduct the advanced characterization of the thermoelectric properties of doped polymers. And the main role in this project of Jiali Guo (ESR6) is to investigate experimentally the structural, electronic and thermal properties of organic and hybrid thermoelectric materials based on their characterization by means of advanced tools and processing methods.
For this purpose, the related experimental works and training activities have been on track. The samples of different polymers exhibiting gradients in microstructure and doping level were produced and the local electrical and thermal conductivity was analyzed using high-spatial-resolution noncontact optical methods – Frequency-domain thermoreflectance (FDTR), as shown in Figure 1, which enables the combinatorial evaluation of TE properties. Based on this technology, they are working to find a general correlation between electrical and thermal transport in polymer systems.
1. Zapata-Arteaga, et al., ACS Energy Lett. 2020, 5, 2972
2. Perez L A, et al., arXiv preprint arXiv, 2021, 2109, 00763
Instituto de Ciencia de Materiales de Barcelona, Spain
Advanced characterization of the thermoelectric properties of organic systems