Voronezh State University, Physics Faculty, General Physics Department, Universitetskaya pl.1, Voronezh, 394018, Russian Federation.
Leibniz Institute of Photonic Technology, Research Department Functional Interfaces, Albert Einstein Str. 9, 07745, Jena, Germany.
Small. 2023 Mar;19(10):e2206322. doi: 10.1002/smll.202206322. Epub 2023 Jan 17.
The composition and atomic and electronic structure of a silicon nanowire (SiNW) array coated with tin oxide are studied at the spectromicroscopic level. SiNWs are covered from top to down with a wide bandgap tin oxide layer using a metal-organic chemical vapor deposition technique. Results obtained via scanning electron microscopy and X-ray diffraction showed that tin-oxide nanocrystals, 20 nm in size, form a continuous and highly developed surface with a complex phase composition responsible for the observed electronic structure transformation. The "one spot" combination, containing a chemically sensitive morphology and spectroscopic data, is examined via photoemission electron microscopy in the X-ray absorption near-edge structure spectroscopy (XANES) mode. The observed spectromicroscopy results showed that the entire SiNW surface is covered with a tin(IV) oxide layer and traces of tin(II) oxide and metallic tin phases. The deviation from stoichiometric SnO leads to the formation of the density of states sub-band in the atop tin oxide layer bandgap close to the bottom of the SnO conduction band. These observations open up the possibility of the precise surface electronic structures estimation using photo-electron microscopy in XANES mode.
采用金属有机化学气相沉积技术，在硅纳米线（SiNW）阵列上从上到下覆盖一层宽带隙氧化锡层，研究了其组成、原子和电子结构。通过扫描电子显微镜和 X 射线衍射得到的结果表明，氧化锡纳米晶的尺寸为 20nm，形成了一个连续且高度发达的表面，具有复杂的相组成，这是导致观察到的电子结构转变的原因。通过光电子显微镜在 X 射线吸收近边结构光谱（XANES）模式下，对包含化学敏感形态和光谱数据的“单点”组合进行了检查。观察到的光谱显微镜结果表明，整个 SiNW 表面都覆盖了一层氧化锡（IV）层，以及氧化锡（II）和金属锡相的痕迹。偏离化学计量的 SnO 导致在 atop 氧化锡层的能带隙中形成了靠近 SnO 导带底部的态密度子带。这些观察结果为使用 XANES 模式的光电子显微镜精确估计表面电子结构提供了可能性。
