guest ::
| Home > Articles > Published articles > Effect of the annealing atmosphere on crystal phase and thermoelectric properties of copper sulfide |
| Home > Articles > Published articles > Effect of the annealing atmosphere on crystal phase and thermoelectric properties of copper sulfide |
(Institut de Recerca en Energia de Catalunya) (Institute of Science and Technology Austria) (Institut de Recerca en Energia de Catalunya) (Institut de Recerca en Energia de Catalunya) (Institut Català de Nanociència i Nanotecnologia) (Universitat Politècnica de Catalunya. Departament d'Enginyeria Química) (Institute of Science and Technology Austria) (Jiangsu University. Institute for Energy Research) (Institució Catalana de Recerca i Estudis Avançats)
| Date: | 2021 |
| Abstract: | Cu2-xS has become one of the most promising thermoelectric materials for application in the middle-high temperature range. Its advantages include the abundance, low cost, and safety of its elements and a high performance at relatively elevated temperatures. However, stability issues limit its operation current and temperature, thus calling for the optimization of the material performance in the middle temperature range. Here, we present a synthetic protocol for large scale production of covellite CuS nanoparticles at ambient temperature and atmosphere, and using water as a solvent. The crystal phase and stoichiometry of the particles are afterward tuned through an annealing process at a moderate temperature under inert or reducing atmosphere. While annealing under argon results in Cu1. 8S nanopowder with a rhombohedral crystal phase, annealing in an atmosphere containing hydrogen leads to tetragonal Cu1. 96S. High temperature X-ray diffraction analysis shows the material annealed in argon to transform to the cubic phase at ca. 400 K, while the material annealed in the presence of hydrogen undergoes two phase transitions, first to hexagonal and then to the cubic structure. The annealing atmosphere, temperature, and time allow adjustment of the density of copper vacancies and thus tuning of the charge carrier concentration and material transport properties. In this direction, the material annealed under Ar is characterized by higher electrical conductivities but lower Seebeck coefficients than the material annealed in the presence of hydrogen. By optimizing the charge carrier concentration through the annealing time, Cu2-xS with record figures of merit in the middle temperature range, up to 1. 41 at 710 K, is obtained. We finally demonstrate that this strategy, based on a low-cost and scalable solution synthesis process, is also suitable for the production of high performance Cu2-xS layers using high throughput and cost-effective printing technologies. |
| Grants: | Ministerio de Ciencia e Innovación RTI2018-093996-B-C31 Ministerio de Economía y Competitividad ENE2017-85087-C3 Ministerio de Economía y Competitividad SEV-2017-0706 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-327 Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-128 |
| Note: | Els autors Xu Han i Chenyang Xie no apareixen a la versió preprint. |
| Note: | Altres ajuts: Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program. |
| Rights: | Tots els drets reservats.  |
| Language: | Anglès |
| Document: | Article ; recerca ; Versió sotmesa a revisió |
| Subject: | Copper sulfide ; Vacancies ; Solution synthesis ; Thermoelectric ; Printing ; Energy conversion |
| Published in: | ACS nano, Vol. 15, issue 3 (March 2021) , p. 4967-4978, ISSN 1936-086X |
26 p, 1.4 MB |
