In-plane optical anisotropy and nonlinear optical effects in 2D InTeO 3 Cl

Anisotropic two-dimensional (2D) materials with low structural symmetry and in-plane optical anisotropy provide a promising platform for the development of polarization-driven photonic devices. Herein, high-quality subcentimetre-scale InTeO3Cl single crystals were prepared using the chemical vapor transport (CVT) method and further exfoliated to flakes of nanometer thickness. The crystal structure, optical anisotropy, bandgap, and stability of 2D InTeO3Cl were extensively investigated. Raman characterization verified the strong in-plane optical anisotropy of 2D InTeO3Cl. Furthermore, it presented an optical bandgap of 2.6 eV and excellent environmental and thermal stability. Interestingly, 2D InTeO3Cl manifested an anisotropic second-harmonic generation (SHG) response, which originated from a centrosymmetry breaking induced by periodic interlayer dislocation. Our work reveals the outstanding in-plane optical anisotropy and nonlinear optical effects of 2D InTeO3Cl and provides a promising candidate for the development of high-performance optical and photonic devices.