Epitaxial Mixed-Dimensional MoS₂ Nanofin-Nanoribbon Hybrids and Their Integration into Electronic and Optoelectronic Devices

Transition metal dichalcogenides, notably MoS₂, have garnered substantial attention owing to their excellent optical and electrical properties. While various methods have been employed to grow MoS₂, resulting in nanostructures with diverse dimensionalities, controlling the lattice orientation and synthesizing aligned nanostructures beyond 2D remain a formidable challenge. In this study, we report the epitaxial growth of aligned MoS₂ nanofin-nanoribbon hybrids, each consisting of a horizontal nanoribbon with a vertical lamellar structure ("fin") in its center. Structural analysis reveals epitaxial relations that induce the growth into three isomorphic orientations following the 3-fold symmetry of the <i>C</i>-plane sapphire substrate. The nanofin-nanoribbon hybrid was integrated into a fin-channel photodetector with response times on the scale of tens of μs and high photocurrent. Furthermore, the nanofin-nanoribbon hybrids are incorporated into n-type "fin-FET" transistors, showing on-off ratios on the order of ∼10³ at room temperature. The performance of these devices is discussed in terms of the efficient fabrication process, devoid of postgrowth steps, and the unique dimensionality of the device, which realizes a high optical path in the fin-shaped channel. This work demonstrates the integration of MoS₂ into efficient fin-channel electronic and optoelectronic devices, laying the foundation for large-scale integration of TMDs into devices with nonstandard channel configurations.