WSe<sub>(2-x)</sub>Te<sub>x</sub> alloys grown by molecular beam epitaxy
Barton, Adam; Yue, Ruoyu; Walsh, Lee; Zhou, Guanyu; Cormier, Christopher; Smyth, Christopher M.; Addou, Rafik; Colombo, Luigi; Wallace, Robert M.; Hinkle, Christopher
Date:
2019-07-18
Copyright:
© 2019, IOP Publishing Ltd. This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after a 12 month embargo period. After the embargo period, everyone is permitted to use copy and redistribute this article for non-commercial purposes only, provided that they adhere to all the terms of the licence https://creativecommons.org/licences/by-nc-nd/3.0
Full text restriction information:
Access to this article is restricted until 12 months after publication by request of the publisher.
Restriction lift date:
2020-07-18
Citation:
Barton, A. Yue, R., Walsh, L., Zhou, G., Cormier, C., Smyth, C. M., Addou, R., Colombo, L., Wallace, R. M. and Hinkle, C. (2019) ‘WSe<sub>(2-x)</sub>Te<sub>x</sub> alloys grown by molecular beam epitaxy’, 2D Materials. doi: 10.1088/2053-1583/ab334d
Abstract:
The growth of WSe(2-x)Tex alloys by molecular beam epitaxy has been demonstrated for the first time to investigate the phase transition from the semiconducting 2H phase to the semi-metallic 1T’ phase as a function of Te concentration. Up to 14% Te incorporation, stable alloys in the semiconducting 2H phase are achieved while above 79% Te incorporation, stable alloys in the semi-metallic 1T’ phase are obtained. Our results indicate the MBE-grown WSe(2-x)Tex alloys exhibit a miscibility gap from 14% to 79% Te concentrations at a growth temperature of 250 °C, a temperature compatible with direct vertical back-end-of-line integration. This miscibility gap results in phase separation of two different alloys, both with different composition and crystal structure. While the alloying of small Te concentrations does indeed result in a desired reduction of the semiconducting bandgap, the phase separation above 14% Te incorporation prohibits bandgap tuning for a wider range of applications. These results highlight the competing energies and kinetics associated with producing uniform WSe(2-x)Tex alloys.
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Except where otherwise noted, this item's license is described as © 2019, IOP Publishing Ltd. This Accepted Manuscript is available for reuse under a CC BY-NC-ND 3.0 licence after a 12 month embargo period. After the embargo period, everyone is permitted to use copy and redistribute this article for non-commercial purposes only, provided that they adhere to all the terms of the licence https://creativecommons.org/licences/by-nc-nd/3.0