Regulating Second Harmonic Generation of Telluromolybdate Materials by Atomic Substitution

Abstract

The second harmonic generation (SHG) is an important nonlinear optical process, which has promising applications in photonics and optoelectronic devices. However, the weak nonlinear response in traditional nonlinear optical crystals limits the applications of SHG. Tellurite molybdenum quaternary oxides (ATeMoO6 ) are an interesting class of nonlinear optical crystals. Substitution of A-site atoms is expected to efficiently modulate the properties. In this paper, nine ATMOs (A= Mn, Fe, Co, Ni, Ru, Ag, Cd, Zn, Mg) were constructed and their electronic properties and SHG responses were studied by first-principles calculations. Our results indicate that the A-site cation substitution can significantly modulate the nonlinear optical properties. ATMOs (A=Ag, Fe, Ru) are ferromagnetic and semi-metallic with 100% spin polarization, which show potential applications in spintronics. The other six ATMOs (A=Mn, Co, Ni, Cd, Zn, Mg) are all semiconductors with strong SHG response in either visible region or infrared region. Specifically, the SHG intensity of CoTeMoO6 in the mid-infrared region (606.64 pm/V) and near-infrared region (534.70 pm/V) is about 10 times of the SHG response value of LiNbO3. This work points out that tellurium molybdate materials have excellent nonlinear optical properties and potential applications in electronics and nonlinear optics.