Theoretical study of the non-linear optical properties of colloids formed by different Au and Ag nanocluster morphologies and molecular organic solvents

Abstract

• Colloidal systems formed by gold and silver nanoclusters. • Theoretical study using density functional theory. • Effects of solvents as water, diethyl ether, benzene, vacuum and, tetrahydrofuran. • Nonlinear optical properties as polarizability, first hyperpolarizability, and second hyperpolarizability. The structural, electronic, and nonlinear optical properties of colloidal systems formed by gold and silver nanoclusters in different molecular organic solvents: water, benzene, diethylether, and tetrahydrofuran were studied from the theoretical point of view by the self-consistent reactions field theory using the polarizable continuum model, under the framework of the density functional theory. The analysis was developed to clarify the effects of the selected solvents in combination with a specific nanocluster structure: cubic, octahedral, tetrahedral, and pentagonal rod. By the discussion of the results, it is exposed that a variety of variables are involved in the obtained nonlinear optical values, such as the macroscopic solvent parameters used by the employed model, where the dielectric constant value is the most significant to describe the behavior of properties as the polarizability and the first and second hyperpolarizabilities. Besides, in the case of morphology, the symmetry of each structure is the most critical factor to consider in tailoring the desired nonlinear optical response. Our results can be used as a reference to the experimental development of non-linear optical devices based on colloids.