论文标题
定量氢化无定形硅中纳米级密度波动
Quantification of nanoscale density fluctuations in hydrogenated amorphous silicon
论文作者
论文摘要
通过小角X射线（SAXS）和中子散射（SANS）（SAN）组合，空间分辨率为0.8 nm。 A-SI：H材料使用一系列广泛的条件沉积，并代表此类材料。我们识别两个不同的阶段，这些阶段嵌入了A-Si：H矩阵中并根据它们的散射横截面进行了量化。首先，检测到形成具有1.6 nm void-to-void距离的超晶格的1.2 nm大小的空隙（具有10多个缺失原子的多变量）。在A-SI：H材料中以高速率沉积的浓度以高达6*10^19 ccm的浓度发现空隙。其次，发现耗尽氢的密集有序域（DOD），平均直径为1 nm。 DOD倾向于形成10-15 nm尺寸的聚集体，并且在此处考虑的所有A-SI：H材料中都在很大程度上发现。这些定量发现使您可以理解A-SI：H的结构和电子性质之间的复杂相关性，并将它们直接链接到缺陷的光诱导的形成。最后，得出了一个结构模型，该模型验证了有关A-Si：H的纳米结构的理论预测。
The nanostructure of hydrogenated amorphous silicon (a Si:H) is studied by a combination of small-angle X-ray (SAXS) and neutron scattering (SANS) with a spatial resolution of 0.8 nm. The a-Si:H materials were deposited using a range of widely varied conditions and are representative for this class of materials. We identify two different phases which are embedded in the a-Si:H matrix and quantified both according to their scattering cross-sections. First, 1.2 nm sized voids (multivacancies with more than 10 missing atoms) which form a superlattice with 1.6 nm void-to-void distance are detected. The voids are found in concentrations as high as 6*10^19 ccm in a-Si:H material that is deposited at a high rate. Second, dense ordered domains (DOD) that are depleted of hydrogen with 1 nm average diameter are found. The DOD tend to form 10-15 nm sized aggregates and are largely found in all a-Si:H materials considered here. These quantitative findings make it possible to understand the complex correlation between structure and electronic properties of a-Si:H and directly link them to the light-induced formation of defects. Finally, a structural model is derived, which verifies theoretical predictions about the nanostructure of a-Si:H.
