Photothermal-reaction-assisted two-photon lithography of silver nanocrystals capped with thermally cleavable ligands

We report an alternative approach to produce micropatterns of metallic nanoparticles using photothermal-reaction-assisted two-photon direct laser writing. The patterns are achieved using a facile surface treatment of silver nanoparticles (Ag NPs) functionalized with thermally cleavable ligands; N-(tert-butoxycarbonyl)-L-cysteine methyl ester. The ligand cleavage initiated by pulsed laser-induced thermal reaction results in a significant change in dispersiblility of the nanocrystals, thereby enabling a solvent-selective development process after photopatterning. We demonstrated that Ag NP patterns with submicron linewidths can be achieved using near infrared pulsed laser illumination.