We present a comprehensive experimental and theoretical study of phonon scattering by nanoprecipitates in potassium-doped PbTe, PbSe and PbS. We highlight the role of the precipitate size distribution measured by microscopy, whose tuning allows for thermal conductivities lower than the limit achievable with a single size. The correlation between the size distribution and the contributions to thermal conductivity from phonons in different frequency ranges provides a physical basis to the experimentally measured thermal conductivities, and a criterion to estimate the lowest achievable thermal conductivity. The results have clear implications for efficiency enhancements in nanostructured bulk thermoelectrics.
@article{arxiv.1810.07344,
title = {Understanding Phonon Scattering by Nano-Precipitates in Potassium-Doped Lead Chalcogenides},
author = {Zhao Wang and Xiaolong Yang and Dan Feng and Haijun Wu and Jesus Carrete and Li-Dong Zhao and Chao Li and Shaodong Cheng and Biaolin Peng and Guang Yang and Jiaqing He},
journal= {arXiv preprint arXiv:1810.07344},
year = {2018}
}