Laser-induced jets of nanoparticles: exploiting air drag forces to select the particle size of nanoparticle arrays

Abstract

In this study, we developed a new method-based on laser-induced jets of nanoparticles (NPs) and air drag forces-to select the particle size of NP arrays. First, the incident wavelength of an excimer laser was varied to ensure good photo-to-thermal energy conversion efficiency. We then exploited air drag forces to select NPs with sizes ranging from 5 to 50 nm at different captured distances. Controlling the jet distances allowed us to finely tune the localized surface plasmon resonance (LSPR) wavelength. The shifting range of the LSPR wavelengths of the corresponding NP arrays prepared using the laser-induced jet was wider than that of a single NP or an NP dimer. We further calculated the relationship between the air drag force and the diameter of the NPs to provide good control over the mean NP size (capture size ≧ 300 μm) by varying the capture distance. Laser-induced jets of NPs could also be used to fabricate NP arrays on a variety of substrates, including Si, glass, plastic, and paper. This method has the attractive features of rapid, large-area preparation in an ambient environment, no need for further thermal annealing treatment, ready control over mean particle size, and high selectivity in the positioning of NP arrays. Finally, we used this method to prepare large NP arrays for acting hot spots on surface-enhanced Raman scattering-active substrates, and 10(-12) M R6G can be detected. Besides, we also prepare small NP arrays to act as metal catalysts for constructing low-reflection, broadband light trapping nanostructures on Si substrates.

Gold nanoparticle transfer through photothermal effects in a metamaterial absorber by nanosecond laser

“…The laser-induced forward transfer (LIFT), as one of the methods, has been extensively studied due to its ability to deposit nanostructures of diverse materials onto different receiver substrates101112131415161718192021222324. However, in previous works, femtosecond laser is typically utilised1011121314151617181920, while only a few of them are realised by nanosecond laser pulses21222324. Due to the high melting point of noble metals that are commonly used (bulk Au 1337K, bulk Ag 1235K, etc.…”

“…), high operating light power is also required. The reported threshold light fluences for metal transferring mostly varied from about 100 mJ/cm 2 to several J/cm 2 11121314151617181920212223, while for those with fluence under 100 mJ/cm 2 , fs-pulse laser is utilised10. Furthermore, only one nanoparticle (NP)12131415161718192021 or a few NPs without regular morphologies11 are transferred by one light shot in most previous reports.…”

“…Furthermore, only one nanoparticle (NP)12131415161718192021 or a few NPs without regular morphologies11 are transferred by one light shot in most previous reports. Large-scale transferring methods are rarely studied1023. In their works, fs-pulse lasers10 or ns-pulse lasers with large fluence (460 mJ/cm 2 )23 are needed, respectively.…”

“…Large-scale transferring methods are rarely studied1023. In their works, fs-pulse lasers10 or ns-pulse lasers with large fluence (460 mJ/cm 2 )23 are needed, respectively.…”