Abstract SiC is always produced forming diamond/SiC composite films owing to the oversaturated doping of Si atoms during the preparation of high emission SiV centers. As a higher refractive index material (n = 2.72), the presence of SiC could possibly lead to inefficient photo-luminescent (PL) collection of SiV centers with total internal reflection. In order to understand such effect, different diamond/SiC films were deposited in a 915 MHz microwave plasma CVD (MPCVD) using the reactive gas of tetramethylsilane (TMS). The microstructure and photoluminescence of SiV centers were systematically investigated. It is found that the addition of TMS gas leads to the formation of cubic β-SiC and the refinement of diamond crystals. At the TMS gas flow of 5 sccm, the concentration of β-SiC is about 10% and the average diamond size is about 98 nm. The film exhibits the optimized PL emission of SiV centers, with the ratio of SiV PL to diamond Raman peak being 21.4. Increasing TMS gas flow leads to the increase of the concentration of β-SiC and the deterioration of PL emission of SiV centers. These results reveal that the introduction of TMS gas at a low flow advances the formation of diamond/SiC film containing high-brightness SiV centers.

中文翻译：

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MPCVD法合成金刚石/碳化硅复合薄膜中的光亮硅空位中心

摘要 在制备高发射 SiV 中心过程中，由于 Si 原子的过饱和掺杂，总是会产生 SiC 形成金刚石/SiC 复合薄膜。作为更高折射率的材料 (n = 2.72)，SiC 的存在可能会导致具有全内反射的 SiV 中心的光致发光 (PL) 收集效率低下。为了理解这种影响，使用四甲基硅烷 (TMS) 的反应气体在 915 MHz 微波等离子体 CVD (MPCVD) 中沉积不同的金刚石/SiC 薄膜。系统地研究了 SiV 中心的微观结构和光致发光。发现TMS气体的加入导致立方β-SiC的形成和金刚石晶体的细化。在 TMS 气流为 5 sccm 时，β-SiC 的浓度约为 10%，平均金刚石尺寸约为 98 nm。该薄膜表现出优化的 SiV 中心 PL 发射，SiV PL 与金刚石拉曼峰的比率为 21.4。增加 TMS 气体流量导致 β-SiC 浓度的增加和 SiV 中心 PL 发射的恶化。这些结果表明，在低流量下引入 TMS 气体促进了含有高亮度 SiV 中心的金刚石/SiC 膜的形成。