從一個氮化銦鎵/氮化鎵量子井結構到塞入銀奈米管內膠體量子點的福斯特共振能量轉換行為

Abstract

本研究是透過在氮化銦鎵/氮化鎵量子井結構上製作銀奈米管，並將膠體量子點的光阻溶液塞入其中，來提升量子井結構向量子點的福斯特共振能量轉移效率。研究顯示這種金屬奈米管設計相較於將量子點置於沒有金屬的氮化鎵奈米洞內，前者的能量轉移效率顯著提升。這樣的結果是因為具金屬側壁的奈米洞中產生了更強的奈米腔體效應，並且表面電漿子耦合也產生關鍵作用。銀奈米管的製作過程包括在量子井模板上製作表面奈米洞，接著沉積指定厚度的銀，然後通過氬離子反應離子蝕刻進行二次濺鍍，最後塞入量子點的光阻溶液。我們比較不同銀沉積厚度及相應不同二次濺鍍時間的樣品，發現銀沉積厚度為30奈米時，可達到最高的福斯特共振能量轉移效率。

By fabricating an Ag nanotube above an InGaN/GaN quantum-well (QW) structure and inserting a photoresist solution of colloidal quantum dot (QD) inside, the efficiency of the Förster resonance energy transfer (FRET) from the QW structure into the QD can be enhanced, when compared with that with QD in a GaN nanohole, i.e., no metal deposition. Such a result is caused by the stronger nanoscale-cavity effect in a nanohole of a metallic sidewall and the surface plasmon coupling with the sidewall metal. The Ag nanotube is implemented through the steps of the surface nanohole fabrication on a QW template, the Ag deposition of a designated thickness, the secondary sputtering via reactive ion etching with Ar ions, and the insertion of the photoresist solution of QD. By comparing the samples of different Ag deposition thicknesses and correspondingly different secondary sputtering durations, it is found that the Ag thickness of 30 nm leads to the highest FRET efficiency.