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通过等离子增强化学气相沉积法 ,制备了本征和掺磷的氢化纳米硅薄膜 (nc- Si:H) ,研究了晶粒尺寸和掺杂浓度对纳米硅薄膜喇曼谱的影响 .结果表明晶粒变小和掺杂浓度增加都使纳米晶粒的 TO模峰位逐渐偏离声子限制模型的计算值 .X射线衍射和高分辨电镜像的结果表明晶粒变小导致硅晶粒应力增加 ,而掺杂使晶粒内部杂质和缺陷增多 ,这些因素破坏了晶粒内晶格的平移对称性 ,进一步减小声子的平均自由程 ,导致实验值偏离理论计算值 .晶格平移对称性的破缺还体现在 ,随晶粒尺寸减小或掺杂浓度增加 ,喇曼谱中 TA、LA振动模的相对散射强度增加 .
The intrinsic and phosphorus-doped hydrogenated nano-silicon films (nc-Si: H) were prepared by plasma-enhanced chemical vapor deposition method, and the effects of grain size and doping concentration on the Raman spectra of the nano-silicon films were investigated. The decrease of the grain size and the increase of the doping concentration make the TO mode peak of the nanocrystalline grains gradually deviate from the calculated value of the phonon confinement model.The results of X-ray diffraction and high resolution electron microscopy show that the smaller the grain size, However, doping increases the internal impurities and defects in the grain, which destroy the symmetry of the lattice in the grain and further reduce the mean free path of the phonon, resulting in deviation of the experimental value from the theoretical value. Breaking is also reflected in the Raman spectrum TA, LA vibration mode relative scattering intensity increases as the grain size decreases or the doping concentration increases.