Effect of Cu F Co-doping on the Properties of AgSnO₂ Contact

The crystal structures, mechanical properties, and electrical properties of Cu doped SnO₂, F doped SnO₂, and Cu F co-doped SnO₂ were studied by using the first-principles method. Meanwhile, AgSnO₂, AgSnO₂-F, AgSnO₂-Cu, and AgSnO₂-Cu-F contacts were prepared by using the sol-gel method for a series of experiments to verify the theoretical analysis. According to the XRD patterns, the doping does not change the structure of SnO₂, but increases its lattice constant and volume. Compared with the single-doped system, the doping formation energy of Cu F co-doped system is the smallest and the structure is more stable. Among the three groups of doping systems, the Cu F co-doped system has the highest shear modulus, Young's modulus, hardness, and Debye temperature, and its mechanical properties and wear resistance are relatively best, and the melting point is also the highest. Cu F co-doping can further narrow the band gap of SnO₂, reduce the electron effective mass and donor ionization energy, increase the electron mobility, and further enhance the conductivity of SnO₂. The wetting angle of SnO₂-Cu-F sample with Ag liquid is 1.15°, which indicates that Cu and F co-doping can significantly improve the wettability of SnO₂ and Ag liquid. AgSnO₂-Cu-F contact has a hardness of 82.03 HV, an electrical conductivity of 31.20 mS⋅m^-1, and a contact resistance of 1.048 mΩ. Cu F co-doping can improve the shortcomings of AgSnO₂ contact properties.