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The ultralow thermal conductivity and tunable thermoelectric properties of surfactant-free SnSe nanocrystals

Most studies to date on SnSe thermal transport are focused on single crystals and polycrystalline pellets that are obtained using high-temperature processing conditions and sophisticated instruments. The effects of using sub-10 nm-size SnSe nanocrystals on the thermal transport and thermoelectric pr...

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Detalles Bibliográficos
Autores principales: Mir, Wasim J., Sharma, Anirudh, Villalva, Diego Rosas, Liu, Jiakai, Haque, Md Azimul, Shikin, Semen, Baran, Derya
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9038065/
https://www.ncbi.nlm.nih.gov/pubmed/35480771
http://dx.doi.org/10.1039/d1ra05182b
Descripción
Sumario:Most studies to date on SnSe thermal transport are focused on single crystals and polycrystalline pellets that are obtained using high-temperature processing conditions and sophisticated instruments. The effects of using sub-10 nm-size SnSe nanocrystals on the thermal transport and thermoelectric properties have not been studied to the best of our knowledge. Here, we report the synthesis of sub-10 nm colloidal surfactant-free SnSe NCs at a relatively low temperature (80 °C) and investigate their thermoelectric properties. Pristine SnSe NCs exhibit p-type transport but have a modest power factor of 12.5 μW m(−1) K(−2) and ultralow thermal conductivity of 0.1 W m(−1) K(−1) at 473 K. Interestingly, the one-step post-synthesis treatment of NC film with methylammonium iodide can switch the p-type transport of the pristine film to n-type. The power factor improved significantly to 20.3 μW m(−1) K(−2), and the n-type NCs show record ultralow thermal conductivity of 0.14 W m(−1) K(−1) at 473 K. These surfactant-free SnSe NCs were then used to fabricate flexible devices that show superior performance to rigid devices. After 20 bending cycles, the flexible device shows a 34% loss in the power factor at room temperature (295 K). Overall, this work demonstrates p- and n-type transport in SnSe NCs via the use of simple one-step post-synthesis treatment, while retaining ultralow thermal conductivity.