Pressure tuneable visible-range band gap in the ionic spinel tin nitride
Angewandte Chemie - International Edition
John Wiley & Sons Ltd.
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Kearney, J., Grauzinyte, M., Smith, D., Sneed, D., Childs, C., Hinton, J., Park, C., et al. (2018). Pressure tuneable visible-range band gap in the ionic spinel tin nitride. Angewandte Chemie - International Edition https://doi.org/10.1002/anie.201805038
The application of pressure allows for systematic tuning of the charge density of a material "cleanly", i.e. without changes to the chemical composition via dopants, and exploratory high pressure experiments can inform the design of bulk syntheses of materials that benefit from their properties under compression. Here, we report the electronic and structural response of semiconducting tin nitride Sn3N4 under compression – a continuous opening of the optical band gap from 1.3 eV to 3.0 eV over a range of 100 GPa, a 540 nm blueshift spanning the entire visible spectrum. The pressure-mediated band gap opening is general to this material across numerous high-density polymorphs, implicating the predominant ionic bonding in the material as the root of its mechanism – fingerprinted by increased charge localisation with reduced volume. The rate of decompression to ambient conditions permits access to recoverable metastable states with varying band gaps energies, opening the possibility of pressure tuneable electronic properties for future applications.
high pressure chemistry, nitride chemistry, laser heating, x-ray techniques
This research was sponsored in part by the National Nuclear Security Administration under the Stewardship Science Academic Alliances program through DOE Cooperative Agreement #DE-NA0001982. Portions of this work were performed at HPCAT (Sector 16), Advanced Photon Source (APS), Argonne National Laboratory. C.P. and J.S.S. acknowledge the support of DOE-BES/DMSE under Award DE- FG02-99ER45775. HPCAT operation is supported by DOE- NNSA under Award No. DE-NA0001974, with partial instrumentation funding by NSF. C.J.P. acknowledges financial support from the Engineering and Physical Sciences Research Council (EPSRC) of the UK under Grant No. EP/P022596/1. C.J.P. is also supported by the Royal Society through a Royal Society Wolfson Research Merit Award. J.A.F.-L. acknowledges substantial computational resources under the project (s752) from the Swiss National Supercomputing Center (CSCS) in Lugano. This research was partially supported by the NCCR MARVEL.
Royal Society (WM150023)
Engineering and Physical Sciences Research Council (EP/P022596/1)
External DOI: https://doi.org/10.1002/anie.201805038
This record's URL: https://www.repository.cam.ac.uk/handle/1810/284596
Attribution 4.0 International
Licence URL: https://creativecommons.org/licenses/by/4.0/