Roberts Dennice M, Bardgett Dylan, Gorman Brian P, Perkins John D, Zakutayev Andriy, Bauers Sage R
Materials Science Center, National Renewable Energy Laboratory, Golden, Colorado 80401, United States.
Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, United States.
Nano Lett. 2020 Oct 14;20(10):7059-7067. doi: 10.1021/acs.nanolett.0c02115. Epub 2020 Sep 29.
Nanoscale superlattices represent a compelling platform for designed materials as the specific identity and spatial arrangement of constituent layers can lead to tunable properties. A number of kinetically stabilized, nonepitaxial superlattices with almost limitless structural tunability have been reported in telluride and selenide chemistries but have not yet been extended to sulfides. Here, we present SnS-TaS nanoscale superlattices with tunable layer architecture. Layered amorphous precursors are prepared as thin films programmed to mimic the targeted superlattice; subsequent low temperature annealing activates self-assembly into crystalline nanocomposites. We investigate structure and composition of superlattices comprised of monolayers of TaS and 3-7 monolayers of SnS per repeating unit. Furthermore, a graded precursor preparation approach is introduced, allowing stabilization of superlattices with multiple stacking sequences in a single preparation. Controlled synthesis of the architecture of nanoscale superlattices is a critical path toward tuning their exotic properties and enabling integration with electronic, optical, or quantum devices.
纳米级超晶格是设计材料的一个极具吸引力的平台，因为组成层的特定特性和空间排列可导致可调谐的性能。在碲化物和硒化物化学领域，已经报道了许多具有几乎无限结构可调谐性的动力学稳定的非外延超晶格，但尚未扩展到硫化物。在此，我们展示了具有可调谐层结构的SnS-TaS纳米级超晶格。制备分层非晶前驱体薄膜，对其进行编程以模拟目标超晶格；随后的低温退火激活自组装形成晶体纳米复合材料。我们研究了每个重复单元由单层TaS和3-7层SnS组成的超晶格的结构和组成。此外，引入了一种分级前驱体制备方法，使得在单次制备中能够稳定具有多种堆叠序列的超晶格。对纳米级超晶格结构进行可控合成是调整其奇异特性并实现与电子、光学或量子器件集成的关键途径。
