Studies of Photoluminescence Enhancement in Fluorescent Gold Nanoclusters

• Main Authors: Huei-Pin Jhong, 鍾慧頻
• Other Authors: Ji-Lin Shen
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/22248112764962745574

碩士 === 中原大學 === 物理研究所 === 98 === In this thesis, we study the enhanced quantum yield of luminescence in fluorescent Au nanoclusters (NCs) with different ligands by photoluminescence (PL) and time-resolved photoluminescence (TRPL). The zere-dimensionality of carriers in Au NCs coated with polyethylene glycol (PEG) (Au NCs@PEG) was demonstrated by temperature dependence of the TRPL. We explore the pronounced increase of luminescence intensity after coating with PEG. The energy of localization is about 1-fold increase at low temperature. Based on studies of fluorescence intensity, carrier lifetime and the radiative lifetime, the intensity of luminescence is increased for 1.56 times. The fluorescent Au nanoclusters after silica coating can improve the quality by the rapid thermal annealing (RTA). The room-temperature luminescence of Au clusters after RTA at 60 ℃is 45-fold increased than that of the untreated sample. In the temperature-dependence studies of PL, we used the rate equation to fit the activation energy that is decreases after RTA. We suggest that the carriers of fluorescent Au NCs have more paths after RTA, leading to the transfer from the high-energy state to the low-energy state.