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采用经表面优化的对称球形团簇作Ｓｉ＿３Ｎ＿４，Ｓｉ晶态量子点的模型，利用紧束缚近似和ｒｅｃｕｒｓｉｏｎ方法研究了它们的电子结构，给出了导带底和价带顶位置随量子点尺寸的变化。得到了３２８原子Ｓｉ＿３Ｎ＿４量子点、３２３原子Ｓｉ量子点的中心原子局域态密度及平均态密度，并讨论了态密度和光谱结构的关系，中心原子局域态密度能较好地描述量子点的光谱，这一点得到了实验结果的证实。
Using the surface-optimized symmetrical spherical clusters as the model of Si_3N_4, Si crystal quantum dots, the electronic structure of the Si_3N_4, Si quantum dots has been studied by using the tight binding approximation and the recursion method. The results show that the conduction band bottom and valence band top positions vary with the quantum dot size Variety. The local atom density and the average density of the central atoms of 328 atomic Si 3 N 4 quantum dots and 323 atomic Si quantum dots are obtained. The relationship between the density of states and the spectral structure is discussed. The state density of central atoms can describe the quantum dot Spectra, this is confirmed by the experimental results.