單光子源之奈米鑽石製備及特性研究

Abstract

鑽石之光學中心缺陷如氮-空位(N-V, nitrogen vacancy)、矽-空位(Si-V)、鎳-氮(Ni-N)可 放出單光子，其波長範圍在500-800 nm，因具有優越的室溫穩定的光學特性，已經證 明可應用於長距離光纖通訊、量子科技中的量子計算與量子密碼學等領域。本研究計 畫擬嘗試用微波電漿化學氣相沉積法成長奈米鑽石，利用先進的材料分析技術瞭解鑽 石形成的行為及氬氣與氮氣等氣體對磊晶之影響，並測量相關的電性與光學性質、奈 米尺寸的量子侷限效應；進而研究鍍膜、離子束等方法添加氮、矽、鎳等元素於奈米 鑽石薄膜之中的條件，以形成光學中心，並探討使其成為導體同時兼具單光子之特性 的可行性，同時利用蝕刻法，製備尺寸100 nm 以下之鑽石晶體，做為高效率單光子源。

Optical centers of defects in diamond, such as nitrogen-vacancy, silicon-vacancy, and nickel-nitrogen, can emit single photons in the range of 500-800 nm. Because of the superior properties and stability of diamond as single photon sources at room temperature, it has been demonstrated in various applications of long-distance optical fiber communication, quantum technology in quantum computing and quantum cryptography. In this study, we attempt to explore the processing technology for diamond nanocrystallites as single photon sources using microwave plasma chemical vapor deposition. From microstructural characterization, formation of the nanocrystalline diamonds and their optical and electrical properties can be understood. Also, the effect of nitrogen and argon gases on epitaxy of diamond during bias-enhanced nucleation will be studied. Furthermore, the quantum confinement effect on diamond in nanometer size will be studied using advance energy-filtering transmission electron microscopy. In the second phase of this study, we will develop technologies for adding elements of nitrogen, silicon, and nickel into the nanocrystalline diamonds to form optical centers, and explore the possibility for diamond to be semiconducting with the capability for emitting single photons. To increase the efficiency of photon emission, diamond crystalline size should be in the range of 100 nm. Therefore, the lithography technology for preparation of individual diamond nanocrystllites with ion implantation would be developed as well.