5 years ago

Enhanced Thermoelectric Performance through Tuning Bonding Energy in Cu2Se1–xSx Liquid-like Materials

Enhanced Thermoelectric Performance through Tuning Bonding Energy in Cu2Se1–xSx Liquid-like Materials
Xun Shi, Pengfei Qiu, Hongyi Chen, G. Jeffrey Snyder, Tiansong Zhang, Kunpeng Zhao, Riley Hanus, Dudi Ren, Chenxi Zhu, Qingfeng Song, Fangfang Xu, Lidong Chen, Anders Bank Blichfeld, Bo B. Iversen
Thermoelectric materials require an optimal carrier concentration to maximize electrical transport and thus thermoelectric performance. Element doping and composition off-stoichiometry are the two general and effective approaches for optimizing carrier concentrations, which have been successfully applied in almost all semiconductors. In this study, we propose a new strategy called bonding energy variation to tune the carrier concentrations in Cu2Se-based liquid-like thermoelectric compounds. By utilizing the different bond features in Cu2Se and Cu2S, alloying S at the Se sites successfully increases the bonding energy to fix Cu atoms in the crystal lattice to suppress the formation of Cu vacancies, leading to greatly reduced carrier concentrations toward the optimal value. Via a combination of the lowered electrical and lattice thermal conductivities and the relatively good carrier mobility caused by the weak alloy scattering potential, ultrahigh zT values are achieved in slightly S-doped Cu2Se with a maximal value of 2.0 at 1000 K, 30% higher than that in nominally stoichiometric Cu2Se.

Publisher URL: http://dx.doi.org/10.1021/acs.chemmater.7b01687

DOI: 10.1021/acs.chemmater.7b01687

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.