銅奈米線之合成

Abstract

本研究成功發展出氣固相反應成長法及電子束誘發成長法來製備奈米銅金屬導線。在氣固相反應成長法中，先將CuCl2與(Me3Si)4Si再室溫中研磨混和。此時CuCl2會被還原成全甲基聚矽烷(PMPS)包覆之CuCl顆粒。接下來將此混合物封於玻璃管中並以473K之溫度燒結。於此步的還原反應中CuCl會被還原成金屬銅奈米顆粒其中約有1~ 5%之產物為具有類似電纜結構的奈米銅線，此奈米線半徑約在20~80nm 寬,長度可延伸至10μm。當以 high vacuum grease 包覆於CuCl外側進行相同的反應時可得到高產率(約50%)之奈米銅線。在以電子束輻照PMPS包覆之CuCl顆粒中可發現殘餘的PMPS影像，並且得到50~200nm之多晶銅奈米線。此實驗亦以電子顯微鏡之影像紀錄了奈米線之成長過程。除了線狀的奈米結構外，也可以發現銅金屬奈米顆粒的產生。PMPS包覆不完全之CuCl顆粒在受到電子束照射後，可發現大量的Cu奈米顆粒。純CuCl顆粒被電子束照射時亦可發現相同的現象。

The Vapor Solid Reaction Growth (VSRG) method and Electron Beam Induced Growth (EBIG) method to prepare copper nanowires have been developed in this reserch. The CuCl2 could be reduced by (Me3Si)4Si to form permethylpolysilane (PMPS) encapsulated CuCl particle at room temperature. Further reduction reaction between CuCl and (Me3Si)4Si at 473K generates bicrystalline cable like copper nanowires with 20 ~ 80 nm diameter and as long as 10 μm length in 1 ~ 5% yield. The twin structure was characterized by electron diffraction (ED) pattern. To improve the yield, other possibilities were explored. Silicone heating oil (DC 200(R) Fluid), vacuum pump oil (Santovac 5) and high vacuum grease (DC 976) are used to coat pure CuCl crystal. High yield of copper nanowires (~50%) is observed in high vacuum grease encapsulated sample. The EBIG process is studied in in situ in TEM. Growth of polycrystalline growth of copper nanowire with 50 ~ 200 nm diameter is induced from PMPS encapsulated CuCl particles. Upon irradiated by convergent electron beam (200KeV) inside a TEM instrument. The study has shown the importance of the PMPS sheath with encloses CuCl, as a soft template to direct the growth.