Accessibility navigation

The onset of copper-ion mobility and the electronic transitions in kesterite, Cu2ZnGeSe4

Mangelis, P., Vaqueiro, P. ORCID:, Smith, R. I. and Powell, A. V. (2021) The onset of copper-ion mobility and the electronic transitions in kesterite, Cu2ZnGeSe4. Journal of Materials Chemistry A, 9 (48). pp. 27493-27502. ISSN 0959-9428

Text (Open Access) - Published Version
· Available under License Creative Commons Attribution.
· Please see our End User Agreement before downloading.

[img] Text - Accepted Version
· Restricted to Repository staff only


It is advisable to refer to the publisher's version if you intend to cite from this work. See Guidance on citing.

To link to this item DOI: 10.1039/D1TA08642A


Kesterite-related phases have attracted considerable interest as earth-abundant photovoltaic and thermoelectric materials. For the kesterite Cu2ZnGeSe4, we have established a direct link between anomalies in the temperature dependence of transport properties and an order -disorder transition. Powder neutron diffraction as a function of temperature reveals an order-disorder transition at 473 K, involving disordering of copper and zinc cations over three crystallographic positions. Vacancies are simultaneously created on the copper-ion sublattice, indicative of the concomitant onset of copper-ion mobility. Differential scanning calorimetry data show a weak thermal signature in this temperature region, typical of a second-order phase transition, which is consistent with the absence of anomalies in the temperature dependence of the unit cell volume. The partial melting of the copper-ion sublattice induces a transition in the electrical-transport properties. The changes in electrical resistivity and Seebeck coefficient suggest this involves a transition from a conventional, activated semiconductor, to a degenerate semiconductor. The entry of an increasing fraction of the copper-ion sub-lattice into a liquid-like state is reflected in a reduction in thermalconductivity above 473 K. The order-disorder phase transition identified here has consequences for the performance of photovoltaic and thermoelectric devices based on kesterites.

Item Type:Article
Divisions:Life Sciences > School of Chemistry, Food and Pharmacy > Department of Chemistry
Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Thermal Analysis (CAF)
Interdisciplinary centres and themes > Chemical Analysis Facility (CAF) > Xray (CAF)
ID Code:101473
Uncontrolled Keywords:Thermoelectric, photovoltaic, kesterite
Publisher:Royal Society of Chemistry


Downloads per month over past year

University Staff: Request a correction | Centaur Editors: Update this record

Page navigation