在本研究中，我們報導了準直、尖針狀、單晶NiSi2奈米線有序陣列在(001)Si基材上之製備及性質。首先，在室溫下藉由結合氧氣電漿修飾奈米球微影術、金催化蝕刻跟多重無電鍍銀催化蝕刻，在(001)Si基材上製備出週期性尖針狀矽晶奈米線陣列。接著，利用傾角薄膜蒸鍍與熱處理製備尖針狀矽化物奈米線。由於尖針狀NiSi2奈米線的有序排列、鋒利尖端、單晶結構及低有效功函數，具有極低啟動電場的優異電子場發射特性。實驗結果呈現出令人興奮的前景，這裡所提出的新方法將提供在製備高效尖針狀矽化物基電子場發射源有序陣列的能力。 在這裡，我們還提出ㄧ種簡單的方法在(001)Si基材上製備準直且具高長寬比之矽晶奈米錐陣列，其僅需ㄧ步驟的金屬催化化學蝕刻製程。通過調整蝕刻時間和雙氧水、氫氟酸及酒精的濃度可以容易地控制矽晶奈米錐的形貌和高度。獲得的高長寬比矽晶奈米錐陣列具有超疏水特性，其水滴接觸角高於150°。觀察到的去濕行為可以用Cassie-Baxter model來解釋。具有矽晶奈米錐結構的矽晶基材在可見光/近紅外光波長區域中也表現出很強的抗反射性能。抗反射性能的增強可歸因於錐形矽晶奈米錐結構所產生的光捕捉效應和漸變折射率。高長寬比矽晶奈米錐優異的寬帶抗反射特性使其成為高效矽基太陽能電池或光偵測器的理想選擇。 ;In this study, we reported the fabrication and characterization of well-ordered arrays of vertical needle-like, single-crystalline NiSi2 nanowires on (001)Si substrates. Firstly, periodic needle-like Si nanowire arrays were fabricated on (001)Si substrates by the oxygen plasma modified nanosphere lithography in conjunction with the Au-assisted catalytic etching process and multiple electroless Ag-assisted catalytic etching process at room temperature. Subsequently, the needle-like silicide nanowires were fabricated by oblique-angle thin-film deposition and heat treatment processes. The vertical needle-like NiSi2 nanowires, owing to their well-ordered arrangement, sharp tips, single-crystalline structure, and low effective work function, exhibit excellent field-emission properties with a very low turn-on field. The obtained results present the exciting prospect that the new approach proposed here will provide the capability to fabricate well-ordered arrays of high-efficiency needle-like in silicide-based field emitters. Here, we also propose a facile method to fabricate vertically-aligned, high-aspect-ratio Si nanocone arrays on (001)Si substrates, which is based solely on a one-step metal-assisted chemical etching process. The morphology and height of Si nanocones can be readily controlled by adjusting the etching time and the concentrations of H2O2, HF, and C2H5OH. The obtained heigh-aspect-ratio Si nanocone arrays have superhydrophobic characteristics with water contact angle higher then 150°. The observed dewetting behavior can be explained by the Cassie-Baxter model. The Si substrates with Si nanocone structures also exhibit strong antireflection properties in the visible/near-IR wavelength regions. The enhanced antireflection properties can be attributed to the light trapping effect and the graded reflective indices resulting from the tapered Si nanocone structures. The excellent broadband antireflection characteristics of high-aspect-ratio Si nanocones make them ideal for applications in high efficiency Si-based solar cells or photodetectors.
