Formation of Self-organized Platinum Nanoparticles and Their Electro-optical Properties
Date Issued
2007
Date
2007
Author(s)
Kang, Chieh-Yu
DOI
zh-TW
Abstract
Formation of Pt nanoparticles or nanoisland films as a function of annealing temperature, initial thickness, underlying substrates, and annealing pressure has been investigated. The particle sizes formed at the higher temperature are larger than those formed at the lower temperature. Moreover, the thicker the initial film is, the larger the particle size is formed. Our investigation also shows the sizes of the metal islands would be affected by different types of substrates and different processes during annealing.
Using the micro-photoluminescence (micro-PL) measurement, we find giant enhancement of self-emission from the Pt nanoparticles in visible light region. The integral intensity of micro-PL for the 49.38-nm Pt nanoparticles is about 38 times of that for the Pt thin film. In addition, the peak wavelength varies from 554 nm to 615 nm as the surface morphology of Pt changes due to different annealing parameters. Extinction spectra show that the wavelength of the localized surface plasmon resonance for the Pt nanoisland film would red-shift with the change of their particle size and aspect ratio. From the studies of the XPS and the XRD, we suggest that the novel optical properties of the Pt nanoparticles and the Pt nanoisland films be related to their surface morphology.
The surface resistance of the post-annealed Pt films has also been measured. For the 5-nm Pt thin films, the surface resisitivity would abruptly increase about 2 orders when annealing temperature is larger than 700 K. This is due to the change of surface morphology. The Pt thin films agglomerates to form the nanoisland films.
Our investigation for the novel optical and electrical properties of the Pt nanoparticles could lead to a wide range of potential applications, including the solar cells, the surface enhanced Raman scattering, and the electro-catalyses.
Subjects
鉑奈米顆粒
退火
侷限場增強
侷限表面電漿共振
表面電阻
platinum nanoparticle
annealing
local field enhancement
localized surface plasmon resonance
surface resistance
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-96-R94941030-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):1112b2e78aec6aee6c82086ccdddeb63