本研究探討氧化鋅(ZnO)半導體薄膜改變氨水濃度、沉積溫度、 熱處理氣氛及熱處理溫度，對薄膜成形性質、吸收率及光電流的影 響。以化學水浴法沉積法(CBD)於ITO 導電玻璃基材上進行鍍膜，來 製備光電極薄膜。利用光電化學原理於水溶液中吸收太陽能，並將其 解離成氫氣應用於氫能發電系統上。 本實驗探討不同氨水溶液濃度下對生成氧化鋅晶型結構之影 響，並比較在不同的晶型結構下，其晶型結構對穿透光譜及光電流性 質之影響。實驗結果發現，氨水濃度在1M、1.8M時，氧化鋅形成六 角柱型粗短及細長之晶型結構，氨水濃度在1.7M時，氧化鋅形成花 瓣狀之晶形結構。當其氨水濃度提升至10M時，而其氧化鋅半導體光 電特性在無施加偏壓下光電流密度可達到約0.17mA/cm2。進一步改 變沉積溫度、熱處理氣氛及熱處理溫度對薄膜沉積的影響；實驗結果 顯示，沉積溫度90℃、真空氣氛熱處理500℃下，氧化鋅薄膜之成膜 性質及吸收率最佳。 實驗結果亦顯示氧化鋅摻雜鎳後，其能隙值、吸收率及光電特性 的影響；在無施加偏壓下光電流密度約0.2mA/cm2。因此，化學水浴 法製備氧化鋅光電極乃成本低廉且製程簡易之方式。 關鍵字：半導體薄膜、化學水浴沉積法、晶型結構、光電流密度 In this study, zinc oxide (ZnO) thin film are formed under different working parameters, and their absorption and photocurrent effect are analyzed. ZnO thin films are deposited on ITO conductive glass substrate by chemical bath deposition (CBD), which is one of the most promising technique owing to its large-scale, cost-effective, environmental-benign and low-temperature advantages. By photoelectrochemical water-splitting, ZnO thin film can be used to produce H2. Firstly, different concentrations of ammonia solution are adapted to form zinc oxide thin film, and the resulting crystal structures are compared. It shows that ZnO particles have short and long hexagonal cylinder shapes at [NH3]=1 and1.8. The short hexagonal cylinder shapes was further transformed to a flower-like structure as ammonia increases to [NH3]=1.7. Experiments show that the photocurrent density of ZnO photoelectrode is nearly 0.17 mA/cm2 at 0 bias. The best forming properties of ZnO film occurs at [NH3]=10. By doping Ni into ZnO the effects on energy gap, absorption and photocurrent density of ZnO thin film is investigated. Photocurrent density of ZnO film is nearly 0.2 mA/cm2 at 0 bias. Therefore, producing ZnO photoelectrode by chemical bath deposition is proved to be a low-cost and simple method. Keyword: Zinc Oxide; crystal structure; photoelectrode; photoelectrochemical; water-splitting
