First principles study on photoelectric and mechanical properties of Ag₄SiO₄, Ag₅SiO₄, Ag₂SiO₃, Ag₆Si₂O₇ and Ag₂Si₂O₅ silver based semiconductor materials

The mechanical, photoelectric and thermal properties of five silver silices-Ag 4 SiO 4 , Ag 5 SiO 4 , Ag 2 SiO 3 , Ag 6 Si 2 O 7 and Ag 2 Si 2 O 5 have been studied by using the first principles plane. The results indicate that Ag 2 Si 2 O 5 exhibits the highest elastic constant C 33 (178.33 GPa), demonstrating the strong compressive resistance along the C -axis, as well as the largest bulk modulus (110.77 GPa) and shear modulus (37.98 GPa). It indicates that Ag 2 Si 2 O 5 has superior resistance to volumetric changes and average bond strength. According to Pugh’s criterion, all five semiconductor materials possess inherent toughness. Ag 4 SiO 4 , Ag 5 SiO 4 , Ag 2 SiO 3 , Ag 6 Si 2 O 7 and Ag 2 Si 2 O 5 all belong to indirect narrow bandgap semiconductors. Ag 2 SiO 3 has the lowest Grüneisen parameter ( γ a = 1.84). The results show that the lattice dynamics of the materials are least affected by external temperature and pressure. Ag 5 SiO 4 exhibits the highest reflectivity (20%) and excellent energy loss function. And the highest static refractive index (2.9). The absorption spectra of Ag 4 SiO 4 , Ag 5 SiO 4 and Ag 2 SiO 3 in the far ultraviolet range (6.2 eV ∼ 15 eV) are more potent than those in the near ultraviolet range (3.2 eV ∼ 6.2 eV), making them suitable for use in semiconductor blackout devices. Ag 5 SiO 4 is an outstanding narrow band-gap semiconductor material with potential applications as a photo-catalytic material responsive to visible light.