Regulating second harmonic generation of telluromolybdate materials by atomic substitution

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nonlinear Optics

Background:

• Second harmonic generation (SHG) is crucial for photonics and optoelectronics.
• Weak nonlinear responses in traditional crystals limit SHG applications.
• Tellurite molybdenum quaternary oxides (ATMOs) are a promising class of nonlinear optical crystals.

Purpose of the Study:

• To investigate the impact of A-site cation substitution on the electronic and SHG properties of ATMOs.
• To identify novel ATMO materials for advanced optical and spintronic applications.

Main Methods:

• First-principles calculations were employed to study nine different ATMO compositions (A = Mn, Fe, Co, Ni, Ru, Ag, Cd, Zn, Mg).
• Electronic band structures, spin polarization, and second harmonic generation responses were analyzed.

Main Results:

• A-site substitution significantly modulates the nonlinear optical properties of ATMOs.
• Ag, Fe, and Ru substituted ATMOs exhibit ferromagnetic and 100% spin-polarized semi-metallic behavior, suitable for spintronics.
• Mn, Co, Ni, Cd, Zn, and Mg substituted ATMOs are semiconductors with strong SHG responses in visible or infrared regions.
• CoTeMoO₆ shows an SHG intensity approximately 10 times higher than LiNbO₃ in the mid- and near-infrared regions.

Conclusions:

• Tellurium molybdate materials possess excellent nonlinear optical properties.
• A-site cation engineering is an effective strategy to tune ATMO properties for photonics and spintronics.
• This study highlights the potential of ATMOs in next-generation electronic and nonlinear optical devices.