Plasmonic nano-printing: large-area nanoscale energy deposition for efficient surface texturing

Femtosecond laser pulses focused onto a dielectric induce ripples on its surface that are useful for photovoltaic and sensing applications. Light-driven excitation of surface charge waves—plasmons—achieves light localization on surfaces down to the deep-subwavelength nanoscale. Now, Hong-Bo Sun of Jilin University in China and co-workers from China and Australia have used surface plasmon polaritons to create permanent surface modifications whose period is smaller than the laser wavelength. They achieved this by using a cylindrical lens to create a line focus for near-infrared ultrashort laser pulses on silicon and zinc sulfide surfaces. This nanoprinting technique is well suited for texturing large areas on a wafer scale, since the patterning speed is determined simply by the repetition rate of the laser used. Potential applications include enhanced light harvesting for solar cells and improved photocatalysis.