Size-Selective Optical Printing of Silicon Nanoparticles through Their Dipolar Magnetic Resonance

ZAZA, CECILIA; IANINA L. VIOLI; GARGIULO, JULIAN; CHIARELLI, GERMÁN; CORTES, EMILIANO; LANGOLF, LUDMILLA; OLMOS, JORGE; BARCIKOWSKI, STEPHAN; MAIER, STEFAN A.; SCHLÜCKER, SEBASTIAN; FERNANDO STEFANI

Washington

Conferencia; Frontiers in Optics + Laser sciences; 2019

Optical Society of America

One of the current challenges of nanotechnology is the assembly of individual colloidal nanoparticles (NPs) in determined positions of a substrate with nanometric precision. This will allow the application of colloidal NPs innano and micro-devices. Optical printing achieves this objective by applying optical forces on the NPs, capturing them from a colloidal suspension and guiding them to predetermined positions of a substrate where they are fixed [1,2]. Although potentially applicable to any colloidal NP, optical printing of colloidal NPs has only been used for plasmonic NPs in a wide range of different sizes and shapes [3-5]In the broad spectrum of existing colloidal NPs, silicon nanoparticles possess unique size-dependent optical properties due to their strong electric and magnetic resonances in the visible range. However, their widespreadapplication has been limited, in comparison to other (e.g., metallic) NPs, because their preparation on monodisperse colloids remains challenging. NPs with size-dependent optical properties can be sorted according to their size usingoptical forces [6, 7]. Here, we demonstrate the size-selective optical printing of Si NPs from a polydisperse colloidal suspension produced by LAL of a Si target [8]. Si NPs are printed on glass substrates using visible lasers. It isshown that the size of the printed NPs can be chosen by tuning the wavelength of the laser beam to the dipolar magnetic resonances. Furthermore, correlated electron microscopy and single particle scattering spectroscopy on theprinted NPs reveal a magnetic dipolar resonance determined by the NP size. This work settles the basis for the optical printing of nanodevices based on HRI colloidal NPs, where the optical properties, size, and position of eachindividual component can be controlled.