Sutter Peter, French Jacob S, Khosravi Khorashad Larousse, Argyropoulos Christos, Sutter Eli
Department of Electrical & Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
Department of Mechanical & Materials Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
Nano Lett. 2021 May 26;21(10):4335-4342. doi: 10.1021/acs.nanolett.1c00891. Epub 2021 May 6.
2D/layered semiconductors are of interest for fundamental studies and for applications in optoelectronics and photonics. Work to date focused on extended crystals, produced by exfoliation or growth and investigated by diffraction-limited spectroscopy. Processes such as vapor-liquid-solid (VLS) growth carry potential for mass-producing nanostructured van der Waals semiconductors with exceptionally high crystal quality and optoelectronic/photonic properties at least on par with those of extended flakes. Here, we demonstrate the synthesis, structure, morphology, and optoelectronics/photonics of GaSe van der Waals nanoribbons obtained by Au- and Ag-catalyzed VLS growth. Although all GaSe ribbons are high-quality basal-plane oriented single crystals, those grown at lower temperatures stand out with their remarkably uniform morphology and low edge roughness. Photoluminescence spectroscopy shows intense, narrow light emission at the GaSe bandgap energy. Nanophotonic experiments demonstrate traveling waveguide modes at visible/near-infrared energies and illustrate approaches for locally exciting and probing such photonic modes by cathodoluminescence in transmission electron microscopy.
二维/层状半导体在基础研究以及光电子学和光子学应用方面备受关注。迄今为止的工作主要集中在通过剥离或生长制备的外延晶体上，并通过衍射极限光谱进行研究。诸如气-液-固（VLS）生长等工艺具有大规模生产纳米结构范德华半导体的潜力，这些半导体具有极高的晶体质量以及至少与外延薄片相当的光电子/光子特性。在此，我们展示了通过金和银催化的VLS生长获得的GaSe范德华纳米带的合成、结构、形态以及光电子学/光子学特性。尽管所有GaSe纳米带都是高质量的基面取向单晶，但在较低温度下生长的纳米带以其显著均匀的形态和低边缘粗糙度脱颖而出。光致发光光谱显示在GaSe带隙能量处有强烈、狭窄的光发射。纳米光子学实验证明了在可见/近红外能量下的行波导模式，并展示了在透射电子显微镜中通过阴极发光局部激发和探测此类光子模式的方法。
