Evolution of morphological and optical properties of self-assembled Ag nanostructures on c-plane sapphire (0001) by the precise control of deposition amount

摘要: Silver (Ag) nanoparticles (NPs) have been widely adapted in various optoelectronic and sensing applications due to the size, shape density dependent tunable properties. In this work, systematic control of configuration self-assembled Ag nanostructures on c-plane sapphire (0001) is demonstrated through solid state dewetting process by variation deposition amount (DA) at two distinctive temperature 400 °C 650 °C. The corresponding morphological evolution systematically discussed based diffusion, Volmer–Weber coalescence growth model. specific, relatively lower °C, evolve three regimes DA control: i.e. dome-shaped NPs between 2 14 nm (regime I), irregular nano-mounds (NMs) 20 40 II), NMs into a layer 60 200 III). Meanwhile, higher regime shift induced enhanced surface diffusion increased thermal energy, connected are resulted even DAs along with gradually DAs. optical properties such as average reflectivity, plasmonic absorption band reflectance maxima (peaks) very sensitively respond spacing plasmon, reflection scattering. Specifically, exhibits strong NIR region weak visible while elongated show region. Furthermore, Raman spectra (A 1g vibrational mode) demonstrate correlation coverage nanostructures.