MoS₂ nanoribbons have attracted increased interest due to their properties, which can be tailored by tuning their dimensions. Herein, the growth of MoS₂ nanoribbons and triangular crystals formed by the reaction between films of MoOx (2<x<3) grown by pulsed laser deposition and NaF in a sulfur-rich environment is demonstrated. The nanoribbons can reach up to 10 µm in length, and feature single-layer edges, forming a monolayer–multilayer junction enabled by the lateral modulation in thickness. The single-layer edges show a pronounced second harmonic generation due to the symmetry breaking, in contrast to the centrosymmetric multilayer structure, which is unsusceptible to the second-order nonlinear process. A splitting of the Raman spectra is observed in MoS₂ nanoribbons arising from distinct contributions from the single–layer edges and multilayer core. Nanoscale imaging reveals a blue-shifted exciton emission of the monolayer edge compared to the isolated MoS₂ monolayers due to built-in local strain and disorder. We further report on an ultrasensitive photodetector made of a single MoS₂ nanoribbon with a responsivity of 8.72 × 10² A W⁻¹ at 532 nm, among the highest reported up-to-date for single-nanoribbon photodetectors. These findings can inspire the design of MoS₂ semiconductors with tunable geometries for efficient optoelectronic devices.

中文翻译：

---

具有增强边缘非线性响应和光响应性的二硫化钼纳米带

MoS ₂纳米带因其可通过调整其尺寸来定制的特性而引起了越来越多的兴趣。在此，证明了通过脉冲激光沉积生长的MoOx(2<x<3)薄膜与NaF在富硫环境中反应形成的MoS 2 纳米带和三角形晶体的_生长。纳米带的长度可达 10 µm，具有单层边缘，通过厚度的横向调制形成单层-多层结。与中心对称多层结构相比，单层边缘由于对称性破缺而表现出明显的二次谐波，而中心对称多层结构不易受二阶非线性过程的影响。_{在 MoS 2}纳米带中观察到拉曼光谱的分裂，这是由于单层边缘和多层核心的不同贡献所致。_{纳米级成像显示，由于内置的​​局部应变和无序，与孤立的 MoS 2}单层相比，单层边缘的激子发射发生蓝移。我们进一步报道了由单个 MoS ₂纳米带制成的超灵敏光电探测器，其在 532 nm 处的响应率为 8.72 × 10 ²  A W ^-1，是迄今为止报道的最高的单纳米带光电探测器之一。_{这些发现可以启发具有可调几何形状的 MoS 2}半导体的设计，以实现高效光电器件。