本實驗引入表面聲波(Surface Acoustic Wave, SAW)偵測的新穎技術，研究金屬奈米顆粒陣列於入射電磁波作用下的光導電特性。電磁波作用在奈米金屬顆粒上，引發金屬奈米顆粒內部的自由電子產生集體性的表面電漿振盪，過程中激發自由電荷重新分布。此研究有利於深入了解表面電漿子主宰之電子傳輸機制；於應用層面，可設計由表面電漿機制主宰的光電元件，例如：光偵測器、光電開關…等。
由於表面聲波對表面的變化極為靈敏，因此我們推測採用表面聲波技術將會比一般使用的電性I-V量測方式具有更靈敏的感測能力，企圖藉此以更有效率的方式進行奈米金屬顆粒陣列之光導電性偵測。
實驗採用128oYcut鈮酸鋰壓電材料搭配線寬5μm的指叉電極作為表面聲波感測元件，共振頻率為189.5MHz；所偵測的奈米顆粒陣列分別為外部修飾十八碳鏈長的正十八硫醇(1-octadecanethiol)分子，粒徑約為6奈米的金、銀奈米顆粒緊密排列(Close-packed)陣列；另外也以非緊密排列(Random)的奈米顆粒陣列作為比較。研究結果顯示：
1. 電性I-V量測以及表面聲波偵測結果皆顯示緊密排列銀奈米顆粒陣列相對於緊密排列金奈米顆粒陣列具有較佳的光導電度，且兩者光導電度與光強度呈線性關係。
2. 採用表面聲波偵測技術相對於電性I-V量測，有較佳的偵測力(訊雜比高約8至20倍)。
3. 觀察不同入射波長之光導電度，發現其趨勢和表面電漿吸收光譜極為一致，故可以此建立一由表面電漿機制所主宰的光導電模型。

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