Photo-induced tunable local oxidation and fragmentation in Pt ultra-nanoclusters functionalized GaN nanotubes

Large scale square-shaped wurtzite-GaN nanotubes are synthesized by a quasi-vapor–solid process. GaN nanotubes, functionalized with ultra-small Pt nanocluster via green chemistry route, provide extraordinary physicochemical properties instigated by laser power exposure and local ambience. Laser irradiation-induced localized catalytic oxidation and catastrophic photo-fragmentation in individual nanotubes is observed as a result of rapid crystallo-chemical transformation. The auto-amplified electronic cascades inside the Pt nanoclusters, upon exposure to high laser fluency, reinforce strong energy deposition in the proximity of the metal–semiconductor interface. This process leads to ballistic recombination with the available photo-generated O2 ionized/radical species to yield chemisorbed oxide layer of Ga2O3. It has been demonstrated to bisect or oxidize a selected region of a single GaN nanotube by modulating the incident laser power, gas ambience, and its kinetics.