銅片上電化學法披覆摻銀氧化鋅奈米柱結構並探討特性

Electrochemical coating of Ag-doped ZnO nanorods on copper plate to study their structure and charatcterization

李國志(Guo-jhih Li)

指導教授 ： 林景崎

國立中央大學/工學院/機械工程學系/碩士(2014年)

摘要

本研究在含2、6、10及14 μM在含硝酸銀及2 mM六亞甲基四胺之2 mM硝酸鋅溶液中，利用三極式定電位法於銅箔表面控制電位在-0.4 V ~ -1.0 V範圍內進行電化學反應，期望獲得摻銀p-型氧化鋅奈米柱之披覆薄膜。披覆膜經SEM觀察顯示：薄膜由六角奈米柱構成，隨著電位增加，薄膜單位面積之奈米柱分佈密度增高，奈米柱直徑也增大。經XRD分析，薄膜所含奈米柱屬於六方纖鋅礦結構之氧化鋅，其(002)結晶面特徵峰隨溶液中銀離子濃度增加而朝小角度偏移，推測銀在氧化鋅中摻雜濃度逐漸增高，使經扭曲而增加(002)晶面之間距。經300 ℃退火1小時後，此(002)繞射峰更尖銳，顯示結晶性更好。披覆膜的XPS分析，經對Ag 3d5/2圖譜去混參處理(deconvolution)，得知其在368.27 eV為Ag+之訊號。以電化學阻抗頻譜之Mott–Schottky法分析，確認所得之摻銀氧化鋅奈米柱電化學披覆膜屬於p-型半導體，所有電化學條件中，在含6 μM，硝酸銀之溶液中，電位控制在-1.0 V所得薄膜，其載子(電洞)濃度最高，約為1.35×1013cm-3。研究成果顯示已可在銅箔表面利用電化學法成功披覆摻銀之p-型氧化鋅奈米柱披構成之薄膜。

關鍵字

電化學合成 ； 薄膜 ； 摻銀氧化鋅 ； 奈米柱 ； p-型半導體

並列摘要

The aim of this work was to prepare p-type semiconducting Ag-doped ZnO thin films consisting of nano rods on a Cu-foil (99% in purity) by three-electrode electrochemical method. The reaction was carried out in a 2 mM zinc nitrate solution containing 2 mM hexamine with 2, 6, 10 and 14 μM silver nitrate at 80 ℃ under constant potentials in the range from -0.4 V to -1.0 V against the reference electrode Ag/(AgCl, sat. KCl). Examining through SEM, the coating comprised hexagonal nanorods with their diameters increasing and their distribution denser with more negative potentials applied in the process. After analysis by XRD, the coatings were identified as wurtzite ZnO crystals preferred at (002). This (002) peak shifted to a lower angle in 2θas the films come from the solution containing higher concentration of silver nitrate; it became sharper post annealing in 300 ℃. The XPS of the coating revealed the Ag 3d5/2 spectra characterized by a peak with binding energy at 368.27 eV (i.e., a signal of AgZn-O in ZnO crystals) after deconvolution. Mott-schottky analysis, conducted through EIS, confirmed that p-type thin films consisting of Ag doped ZnO nanorods could be successfully prepared by electrochemical method. The film prepared at -1.0 V in the zinc nitrate containing 6 μM silver nitrate revealed the highest carry concentration (at 1.35×1013 cm-3).

並列關鍵字

Electrochemical method ； thin film ； Ag doped ZnO ； nanorods ； p-type ZnO

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