Silicon is the most widely used semiconductor material for electronics and energy related applications. Herein, different Si nanostructures with various shapes, sizes and morphologies are fabricated by a simple, low-cost and versatile metal‐assisted chemical etching (MACE) technique using Ag nanoparticles as a catalyst, deposited on Si surface. The influence of etching time, temperature and intrinsic properties of the silicon substrate (e.g., orientation, crystallinity) on the basic process are studied. Fast preparation of porous silicon (PSi) was achieved on Si 〈1 0 0〉 at room temperature after only 30 s of exposure to etching solution. Meanwhile increased etching time led to increase the pore diameter and a well-aligned SiNWs was obtained after 10 min. However, the exposure of Si 〈1 0 0〉 to the etching solution at 60 °C for only 2 min produced a homogenous and dense SiNWs layer. Additionally, the orientation of Si wafer was found to play a key role during the MACE process. Particularly, the MACE has no effect on Si 〈1 1 1〉 before 30 min whereas a zigzage PSi was formed. PSi nanostructures with straight and zigzag structures were successfully fabricated for the first time in addition to well-aligned, uniform and vertical Si nanowires (SiNWs) with smooth and polygonal shapes. The as-prepared Si nanostructures are characterized by various techniques including field emission-scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), UV–vis. and photoluminescence spectroscopy (PL). The optical properties of as-prepared Si nanostructures are enhanced and the reasons for this improvement and its correlation with the morphology difference are presented and discussed.

硅是用于电子和能源相关应用的最广泛使用的半导体材料。在此，通过简单，低成本和通用的金属辅助化学刻蚀（MACE）技术，以银纳米颗粒为催化剂，在硅表面沉积了各种形状，大小和形态的硅纳米结构。研究了蚀刻时间，温度和硅衬底的固有特性（例如，取向，结晶度）对基本工艺的影响。仅在暴露于蚀刻溶液30 s后，即可在室温下在Si 〈1 0 0〉上快速制备多孔硅（PSi）。同时，增加的蚀刻时间导致孔径增加，并且在10分钟后获得了排列良好的SiNWs。然而，将Si 〈1 0 0〉暴露于60°C的蚀刻溶液中仅2分钟，即可形成均匀且致密的SiNWs层。另外，发现硅晶片的取向在MACE工艺中起关键作用。特别是，MACE在30分钟之前对Si 〈1 1 1〉没有影响，而形成了锯齿形PSi。除了具有平滑和多边形形状的良好排列，均匀和垂直的Si纳米线（SiNWs）外，首次成功制造了具有直线形和锯齿形结构的PSi纳米结构。所制备的Si纳米结构具有多种技术特征，包括场发射扫描电子显微镜（FE-SEM），X射线光电子能谱（XPS），UV-vis。和光致发光光谱（PL）。