Enhanced Cross-plane Thermoelectric Transport of Rotationally-disordered SnSe<sub>2</sub> via Se Vapor Annealing

ORAL

Abstract

In this talk I will review our recent progress in cross-plane thermoelectric measurements of SnSe and SnSe2 films grown by the modulated element reactant (MER) approach. The initially grown SnSe films have relatively low cross-plane Seebeck coefficients due to significant unintentional doping originating from Se vacancies. By performing post-growth annealing at a fixed Se partial pressure, a transition from SnSe to SnSe2 is induced. This results in a 16-fold increase in the cross-plane Seebeck coefficient (from -38.6 to -631μV/K) after Se annealing due to both the SnSe to SnSe2 transition and the mitigation of unintentional doping by Se vacancies. The power factor S2σ increased by 44X after Se annealing. We believe that these results demonstrate a robust method for mitigating unintentional doping in a promising class of materials for thermoelectric applications.1

1. Chen, J.; Hamann, D. M.; Choi, D. S.; Poudel, N.; Shen, L.; Shi, L.; Johnson, D. C.; Cronin, S. B., Enhanced Cross-plane Thermoelectric Transport of Rotationally-disordered SnSe2 via Se Vapor Annealing. Nano Letters 2018.

*DOE Nos. DE-FG02-07ER46376 , DE-FG02-07ER46377 , and NSF Award No. 1402906.
NSF Grant DMR1710214.
NSF GRFP No. 1309047.

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Presenters

  • Jihan Chen

    • University of Southern California

Authors

  • Jihan Chen

    • University of Southern California

  • Danielle Hamann

    • University of Oregon

  • David Choi

    • University of Texas, Austin

  • Nirakar Poudel

    • University of Southern California

  • Lang Shen

    • University of Southern California

  • Li Shi

    • University of Texas, Austin
    • University of Texas at Austin

  • David Johnson

    • University of Oregon

  • Steve Cronin

    • University of Southern California