此研究使用三五族半導體材料中的氮化鎵作為光電化學反應之工作電極用於電解水產生氫氣。為了有效的增加產氫效率將電極改變成為延伸至底部的指叉狀電極，希望可以藉由減短電子行經的路徑進而增加收集電子的能力。藉由磊晶再成長技術將金屬電極嵌入至半導體中，使用二氧化矽作為遮罩蓋在半導體上，沒有被包覆住的部分會有選擇性成長現象且會有不同極性面產生，此研究探討選擇性成長的氮化鎵的光電化學反應效應。

為了承受金屬有機化學氣相沉積磊晶過程中的高溫，金屬材料的選擇上需要考量到熔點溫度且不影響成長完後氮化鎵的表面狀態，金屬作為指叉狀電極延伸至底部，在電性方面再成長過後與氮化鎵需要有歐母接觸。金屬鎢滿足上述的條件，且可以透過磁控濺鍍的方式在常溫下就可以沉積，故選用他作為指叉狀電極的材料。實驗過程中發現金屬鎢在磊晶再成長過程後，電極下方的氮化鎵表面會有被蝕刻現象，要改善此情形在氮化鎵基板上方成長一層高摻雜的氮化鋁鎵層解決表面被蝕刻現象。

使用恆電位儀連接半導體工作電極及白金相對電極還有銀/氯化銀參考電極，泡入氯化鈉電解液中進行光電化學量測。結果顯示使用鎢作為指叉狀電極有可以有效降低起始電壓及提高在零偏壓下的光電流值。由於電子在半導體內部行走的路徑大幅降低，相對的減少移動過程中被缺陷所捕獲的機率。選擇性成長後產生的半極性面會吸收散射光，有效增加光電化學反應能力。光電流表現提升相對的光電化學電解水產生氫氣的能力也增加。

This study used III-V semiconductor material gallium nitride as a working electrode for photoelectric chemical reaction of electrolysis of water to produce hydrogen. By epitaxial regrowth techniques metal electrodes embedded in the semiconductor using SiO2 as a mask cover the semiconductor.The choice of metal material to the melting point and does not need to consider the influence of surface state after growing gallium nitride. Tungsten satisfy the above conditions. During the experiment found that tungsten in the epitaxial growth process again, gallium nitride will be below the surface of the electrode is etched phenomenon, to improve this situation in the gallium nitride layer over the substrate to grow high-doped aluminum gallium nitride surface layer resolved etched phenomenon.
Use potentiostat connecting the semiconductor working electrode and the counter electrode of platinum as well as silver / silver chloride reference electrode, soak into the sodium chloride electrolyte were photoelectrochemical measurements. The results showed that the use of tungsten as an interdigitated electrode has effectively reduced starting voltage and improve the light current at zero bias. Due to significantly reduce the electron within the semiconductor walking path, a relative decrease in the probability of being captured by the defect during the move. Semi-polar surface produced after a selective growth will absorb stray light, effectively increasing the photoelectrochemical reaction capability. Capability to enhance performance relative photocurrent photoelectrochemical electrolysis of water to produce hydrogen gas also increases.

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