To explain the deviation in the valence subband energy levels of the Si(111) inversion layer obtained by experiments and calculations, the band edge profile that has the same subband levels as the experimental results is searched through numerical calculations. The obtained band edge profile is characterized by its flat feature in the subsurface region over 1.2nm from the surface of the Si substrate. By taking the second derivative of the obtained band edge profile, the carrier distribution in the space charge layer is obtained, and the existence of negative charges in the subsurface region is revealed. The origin of the negative charges is attributed to the inhomogeneous valence electron distribution due to the standing wave formation in the narrow space charge layer.

为了解释实验和计算得到的Si(111)反型层价子带能级的偏差，通过数值计算寻找与实验结果具有相同子带能级的带边轮廓。获得的带边缘轮廓的特征在于其在离 Si 衬底表面 1.2nm 以上的表面下区域中的平坦特征。通过对得到的带边轮廓进行二阶导数，得到空间电荷层中的载流子分布，揭示了亚表面区域负电荷的存在。负电荷的起源归因于窄空间电荷层中驻波形成导致的价电子分布不均匀。