Self-assembly of Pt nanoparticles and their localized surface plasmon-enhanced effects on the optical properties of the polymercrystalline ZnO thin films

In this work, we report that Pt nanoparticles are self-assembled by annealing Pt thin films grown on Si (100) substrates at a high temperature. After growth of Pt thin films, annealing treatment is carried out at 700 and 850 °C respectively, under high purity nitrogen environment. It is found that Pt nanoparticles are formed at annealing temperature of 700 °C, while larger sized and high-quality crystalline Pt nanoparticles are generated at an elevated temperature of 850 °C. It is also found that Pt nanoparticles present plasmon enhanced effect on the optical properties of the polymercrystalline ZnO thin films, and Pt nanoparticles prepared by 20s sputtering time leads to about 5 fold excitation enhancement compared to that without Pt nanoparticles.