Mir Wasim J, Sharma Anirudh, Villalva Diego Rosas, Liu Jiakai, Haque Md Azimul, Shikin Semen, Baran Derya
King Abdullah University of Science and Technology (KAUST), KAUST Solar Center (KSC), Physical Sciences and Engineering Division (PSE) Thuwal 23955-6900 Saudi Arabia
King Abdullah University of Science and Technology (KAUST), KAUST Catalysis Center (KCC), Division of Physical Science and Engineering (PSE) Thuwal 23955-690 Kingdom of Saudi Arabia.
RSC Adv. 2021 Aug 19;11(45):28072-28080. doi: 10.1039/d1ra05182b. eCollection 2021 Aug 16.
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 K and ultralow thermal conductivity of 0.1 W m K 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 K, and the n-type NCs show record ultralow thermal conductivity of 0.14 W m K 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 the use of simple one-step post-synthesis treatment, while retaining ultralow thermal conductivity.
迄今为止，大多数关于SnSe热传输的研究都集中在使用高温处理条件和精密仪器获得的单晶和多晶颗粒上。据我们所知，使用尺寸小于10nm的SnSe纳米晶体对热传输和热电性能的影响尚未得到研究。在此，我们报告了在相对较低温度（80°C）下合成尺寸小于10nm的无表面活性剂SnSe纳米晶体，并研究了它们的热电性能。原始的SnSe纳米晶体表现出p型传输，但在473K时功率因子仅为12.5μW m K，热导率极低，为0.1W m K。有趣的是，用碘化甲铵对纳米晶体薄膜进行一步合成后处理，可以将原始薄膜的p型传输转变为n型。功率因子显著提高到20.3μW m K，n型纳米晶体在473K时热导率低至0.14W m K，创历史记录。然后，这些无表面活性剂的SnSe纳米晶体被用于制造柔性器件，其性能优于刚性器件。经过20次弯曲循环后，柔性器件在室温（295K）下功率因子损失34%。总体而言，这项工作展示了SnSe纳米晶体中的p型和n型传输，以及使用简单的一步合成后处理方法，同时保持了极低的热导率。
