Departamento de Electricidad y Electrónica, Universidad de Valladolid, E.T.S.I. de Telecomunicación, Paseo Belén 15, E-47011 Valladolid, Spain.
J Phys Condens Matter. 2014 Mar 5;26(9):095001. doi: 10.1088/0953-8984/26/9/095001. Epub 2014 Feb 12.
We investigate the structural and electronic properties of the interface between hydrogenated amorphous silicon (a-Si:H) and crystalline silicon (c-Si) by combining tight-binding molecular dynamics and DFT ab initio electronic structure calculations. We focus on the c-Si(100)(1×1)/a-Si:H, c-Si(100)(2×1)/a-Si:H and c-Si(111)/a-Si:H interfaces, due to their technological relevance. The analysis of atomic rearrangements induced at the interface by the interaction between H and Si allowed us to identify the relevant steps that lead to the transformation from c-Si(100)(1×1)/a-Si:H to c-Si(100)(2×1)/a-Si:H. The interface electronic structure is found to be characterized by spatially localized mid-gap states. Through them we have identified the relevant atomic structures responsible for the interface defect states, namely: dangling-bonds, H bridges, and strained bonds. Our analysis contributes to a better understanding of the role of such defects in c-Si/a-Si:H interfaces.
我们通过结合紧束缚分子动力学和 DFT 从头算电子结构计算，研究了氢化非晶硅(a-Si:H)和晶体硅(c-Si)之间界面的结构和电子性质。我们主要关注 c-Si(100)(1×1)/a-Si:H、c-Si(100)(2×1)/a-Si:H 和 c-Si(111)/a-Si:H 界面，因为它们具有技术相关性。通过分析 H 和 Si 之间相互作用引起的界面原子重排，我们确定了导致 c-Si(100)(1×1)/a-Si:H 向 c-Si(100)(2×1)/a-Si:H 转变的相关步骤。界面电子结构被发现具有空间局域的带隙中间态。通过它们，我们确定了导致界面缺陷态的相关原子结构，即：悬键、H 桥和应变键。我们的分析有助于更好地理解这些缺陷在 c-Si/a-Si:H 界面中的作用。
