无模板电化学沉积生成附着一维针尖或二维薄膜结构的ZnO纳米柱阵列

Two-step Growth Mechanisms of ZnO Nanorod Arrays Covered with Nano-tapersor Nano-films via Non-template Electrochemical Deposition

采用无模板电化学沉积,以n型(100)硅片为衬底,生成ZnO纳米柱阵列,并在不同条件下进行二次生长,分别在纳米柱表面生成一维针尖与二维薄膜结构.通过场发射扫描电镜图片(FESEM)和X光散射谱(XRD)研究了二次生长机理.结果表明,电流密度高低控制ZnO二次生长形貌:大沉积电流在纳米柱表面生成沿c轴取向针尖;小电流则容易形成沿a轴取向薄膜结构.

ZnO nanorod arrays （NRAs） covered with 1-dimension （l-D） nano-tapers or 2-D nanofilms have been achieved onto the n-type （100） silicon substrates via non-template electrochemical deposition by two steps. The growth mechanisms were studied by filed-emission SEM （FE-SEM） and X- ray Diffraction （XRD）. The results show that the current density applied in the secondary depositional step determines the final structure：the high current density leads the ZnO nano-tapers to grow along caxis; otherwise,the low current density results in the a-axis growth.