| Summary: | 碩士 === 國立中興大學 === 化學系所 === 98 === Highly quantum yield(~47%), highly stable and well-dispersed water- soluble CdSe quantum dots were successfully prepared by using one-pot synthesis method. No functional group for exchanging was used in our method. Furthermore, we also demonstrated that a new type of hybrid material of self-assembling the nanoparticles into PVA host into pearl-necklace nanoclusters with highly-luminescent (~18-fold enhancement) would be obtained through a sol-gel method.
We supposed that the intermolecular hydrogen bonding and electrostatic interaction play an important role in forming pearl-necklace like CdSe /PVA nanoclusters. In the presence of Tris-HCl buffer, the positively charged amines of Tris(hydroxymethyl) aminomethane complex with the negatively charged MPA and EDPA molecules stabilizing quantum dots via electrostatic attraction, then the formation of hydrogen bonding between Tris and PVA molecules result in gradually self assembly aggregation.
Importantly, we transfer the CdSe/PVA hybrid material to solid state architecture by using solvent induced phase separation method, followed by freeze-drying technique to maintain the pore structure. Under 405 nm InGaN/GaN LED chip excitation, we find that the CdSe/PVA monoliths exhibit a high purity green luminescence with luminous efficiency of 7.6 lm/W.
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