- 學位論文
以低溫水溶液沉積法製備高品質氧化鋅奈米柱薄膜及紫外光電阻式感測器
High Quality Zinc Oxide Nanorod Film and Ultraviolet Resistive Photodetector Prepared by Low Temperature Aqueous Solution Deposition
摘要
在本研究中，我們利用濺鍍方式於藍寶石基板上沉積ZnO晶種層，再以水溶液沉積法於50度低溫生長ZnO薄膜並製成紫外光感測器量測其相關的電性及光性等特性。在光致螢光(PL)的分析可以得知，退火處理的氧化鋅奈米柱薄膜於紫外光激發峰值的位置約位於376 nm，而在綠-黃色光約位於550~650 nm有峰值的出現，文獻指出為此為氧化鋅內部缺陷，由實驗可得知在退火處理下，可以填補氧化鋅內部缺陷進而改善晶體品質。接著於ZnO薄膜上蒸鍍指叉式電極，製成紫外光電阻感測器並量測其光響應。我們可以得到，以笑氣於400 oC退火過的氧化鋅薄膜製成的紫外光電阻式感測器開關電流比為144.15，上升時間為2.5秒，下降時間為410秒。再來是以銀製作大尺寸電極以降低接觸電組，其開關電流比為2538.49，上升時間為1.5秒，下降時間為51.5秒。此外以硫化銨對氧化鋅薄膜進行硫化處理後，整體光響應退步，推測原因可能是氧化鋅薄膜與電極介面殘留的硫化物所導致的。最後以ZnO薄膜製作MOS電容器並量測其電容，量測結果顯示其有相當嚴重的介面電荷問題。
並列摘要
In this study, we grow zinc oxide (ZnO) nanorod array and nanorod film with aputtered ZnO seed layer on sapphire substrates by aqueous solution deposition (ASD) at 50 oC. Characteristics of the ZnO nanorod film will be investigated. The PL analysis of ZnO nanorod film shows the typical emissions of narrow exciton related UV band peak at 376 nm and broad defect related green–yellow (550~650 nm) bands is likely due to oxygen vacancies and the emission is improved after annealing. Inter-digital electrode was evaporated on ZnO nanorod film to fabricate ZnO UV photodetector and measure photorespond. We obtain that the current ratio of photodetector with ZnO nanorod film annealed at 400 oC in N2O is 144.15, the rise time is 2.5 sec, the decay time is 410 sec. We also use Ag for large area electrode to decrease contact resistance, the current ratio is 2538.49, the rise time is 1.5 sec, the decay time is 51.5 sec. We use (NH4)2S to passivate the ZnO film surface. The photorespond decrease because the sulfide left at the interface of ZnO film surface and electrode. We fabricate a Al/ALD-Al2O3/ZnO MOS capacitor and measure the capacitance, the result shows there is a serious interface charge problem.