Growth orientation control of metal nanostructures using linearly polarized light irradiation

Controlled orientation of metal nanostructures on a solid substrate was realized by irradiating a pre-deposited nanoseed layer with linearly polarized light in a growth solution containing metal cations. The resulted nanostructures showed the different transmittance spectra for two orthogonal polarized lights, which indicated an anisotropic growth induced by polarized light. The investigation on the growth conditions demonstrated that the wavelength of the irradiated light and the existence of cetyl cetyltrimethylammonium bromide used as surfactant could affect the anisotropic degree of the oriented nanostructures. It was suggested that the polarized lights enhanced the anisotropic local electric field of Au seed nanoparticles, which resulted in the oriented growth of metal nanostructures during the reduction process in the solution. The approach reported in this work can be used in the device fabrication based on oriented metal nanostructures, such as photocatalysts or optical sensors.