Third-order Optical Nonlinearity Investigations of axially linked hyperbranched lanthanum phthalocyanine-boron nitride nanosheets

Abstract

Abstract Developing nonlinear optical materials with wide wavelength range for optical confinement is of wide application prospects and immense scientific interest. In the present work, a novel nanohybrid materials (HLaPc-BNNSs) was designed through axially covalent connected boron nitride (BN) to phthalocyanine. The third-order nonlinear optical properties of HLaPc-BNNSs in organic solvents and polymer matrix were investigated separately. The HLaPc-BNNSs nanohybrid exhibits a wide limiting range and its nonlinear optical properties show a significant improvement in the near-infrared region. In addition, the solid film samples exhibit better uniformity and excellent nonlinear optical response compared to the solution samples. The nonlinear absorption coefficient (β) of the HLaPc-BNNSs/PPSU films is as high as 1800 (cm/GW), which is almost 200 times higher than that of the 532 nm solution absorption coefficient. Possible mechanisms of optical confinement were explored by various methods, including UV-vis absorption, fluorescence, and Z-scan. It is demonstrated that the synergistic effect of two-photon absorption with reverse saturable absorption and charge transfer between BNNSs and HLaPc are important factors in determining its nonlinear optical response and optical limiting performances. Therefore, the preparation of axially connected hyperbranched phthalocyanines and two-dimensional nanomaterials is a new strategy for the design and development of high-efficiency optical limiting functional nano-hybrid materials.