Y-W掺杂AgSnO2触头材料电性能理论分析

AgSnO2作为电接触材料，电寿命低于AgCdO材料，为了提高AgSnO2材料的导电性，对SnO2材料进行掺杂研究。利用第一性原理，通过原子替代的方法，分别用Y、W元素单掺SnO2以及共掺的形式，将SnO2中的Sn元素以16.7%的比例进行原子替换，计算掺杂后SnO2的晶格参数、能带结构、态密度和电荷布居。结果表明：掺杂后的SnO2晶胞，体积增大。通过能带和态密度分析得出，单掺与共掺之后的材料导带底部和价带顶部均向费米能级靠近，共掺之后Y的4d轨道使导带宽度变窄，Y的4d轨道和W的5d轨道同时作用，形成杂质能级，帮助电子跃迁，导电性增强。共掺后原子的成键方式改变，新生成Y-O键和W-O键。共掺后的材料比单掺更能增加SnO2的导电性，为之后AgSnO2触头材料的研究提供了理论依据。

Theoretical Analysis of Electrical Properties of Y-W Co-doped AgSnO2 Contact Materials

As an electrical contact material, the electrical life of AgSnO2 is lower than AgCdO material. In order to improve the electrical conductivity of the AgSnO2 material, doping research on the SnO2 part was performed. Using the first principle, the atomic substitution method is used to form single and co-doped SnO2 with Y and W elements. Atomic replacement of the Sn element in SnO2 by 16.7%, and the lattice parameters, energy band structure, state density and charge layout of doped SnO2 were calculated. The results showed that the volume of doped SnO2 cells increased. Through the analysis of energy band and state density, it can be found that the bottom of the conductance band and the top of the valence band of materials with single mixing and co-mixing are close to the Fermi energy level. After the co-mixing, Y''s 4d orbital makes the conductance band narrow. The 4d orbital of Y and the 5d orbital of W act at the same time, forming impurity levels, helping electron transition, and enhancing conductivity. The bonding mode of atoms is changed, and the new y-o bond and w-o bond are formed, and the ionic type is enhanced and the conductivity is increased. The co-doped materials can increase the electrical conductivity of SnO2 more than the single-doped materials, which provide theoretical basis for the subsequent research on AgSnO2 contact materials.