This thesis aims to study external field induced alignment of semiconductor quantum dot by utilizing single molecule spectroscopy.
Wurtzite structure semiconductors, such as CdSe, exhibit strong electric dipole moment along its c-axis. It is proposed that quantum dot can be aligned along the applied field with sufficient strength. Experiments with two kind of matrix: PMMA mixing with wax, and liquid crystal thin film, were performed for that quantum dots are able to rotate freely in the matrix. Experiments with PMMA matrix were also performed as its rigid matrix for comparison. Interdigitated structure electrodes was deposited on the cover glass for the electric field experiments.
The topical transition (absorption and emission) of CdSe quantum dots has a bright plane perpendicular to its c-axis, and a dark axis along the c-axis. It thus used for characterizing the field alignment. For each observing quantum dot, we record the fluorescence intensity, anti-bunching, polarization anisotropy, and fluorescence lifetime information. In addition, we also analyze the fluorescence correlation spectroscopy to probe the small modulation signal from the fluctuating fluorescence intensity. However, the results indicate that we didn¡¦t observe the field induced change with the field up to 1E7(v/m).
Identifer | oai:union.ndltd.org:NSYSU/oai:NSYSU:etd-0716106-201139 |
Date | 16 July 2006 |
Creators | Lee, Chang-yeh |
Contributors | Bae-heng Tseng, Chao-kuei Lee, Jui-hung Hsu |
Publisher | NSYSU |
Source Sets | NSYSU Electronic Thesis and Dissertation Archive |
Language | Cholon |
Detected Language | English |
Type | text |
Format | application/pdf |
Source | http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0716106-201139 |
Rights | not_available, Copyright information available at source archive |
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