Thiol-stabilized PbS quantum dots （QDs） with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol （TGL/DTG） were coUoidally prepared at room temperature. Room temperature photoluminescence quan...Thiol-stabilized PbS quantum dots （QDs） with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol （TGL/DTG） were coUoidally prepared at room temperature. Room temperature photoluminescence quantum efficiency of freshly prepared PbS QDs （7%-11%） remained higher than 5% upon aging for three weeks when the nanocrystals （NCs） were stored in an ice-bath in the dark, and higher than 5%for at least five weeks when extra DTG ligands were introduced into the nanocrystal solution followed by stirring every two weeks. Poly（N-isopropyl acrylamide） （PNIPAM） microgels were produced via precipitation polymerization with dimensions of ca. 230 nm and polydispersity of 3-5%. Incorporation of PbS QDs into PNIPAM microgels indicated that PbS can be incorporated into the interior of microgel particles and not at the microgel interface. The combination of reasonable room temperature quantum efficiency and strong, efficient luminescence covering the 1.3-1.55 μm telecommunication window makes these nanoparticles promising materials in optical devices and telecommunications.展开更多
A new kind of polyfluorene containing oxadiazole as the side chain was synthesized. The introduction of oxadiazole moiety as more bulky group prevents the aggregation and reduces the crystallinity of the polymers. Eff...A new kind of polyfluorene containing oxadiazole as the side chain was synthesized. The introduction of oxadiazole moiety as more bulky group prevents the aggregation and reduces the crystallinity of the polymers. Efficient intramolecular energy transfer from oxadiazole moiety to the conjugated backbone has been realized, leading to 70% improvement of photoluminescence quantum efficiency of the designed polymers. Compared with PAF, the PFOXD exhibits significant improvement in electroluminescence properties, with luminous efficiency of 0.8 cd/A and maximum luminance of 1800 cd/m2.展开更多
基金NSFC(No.50543007)Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry)+1 种基金NSF of Guangdong Province (No.07006838)Tianhe Bureau of Sci. & Techno., Guangzhou.
文摘Thiol-stabilized PbS quantum dots （QDs） with dimensions 3-5 nm capped with a mixture of 1-thioglycerol/dithioglycerol （TGL/DTG） were coUoidally prepared at room temperature. Room temperature photoluminescence quantum efficiency of freshly prepared PbS QDs （7%-11%） remained higher than 5% upon aging for three weeks when the nanocrystals （NCs） were stored in an ice-bath in the dark, and higher than 5%for at least five weeks when extra DTG ligands were introduced into the nanocrystal solution followed by stirring every two weeks. Poly（N-isopropyl acrylamide） （PNIPAM） microgels were produced via precipitation polymerization with dimensions of ca. 230 nm and polydispersity of 3-5%. Incorporation of PbS QDs into PNIPAM microgels indicated that PbS can be incorporated into the interior of microgel particles and not at the microgel interface. The combination of reasonable room temperature quantum efficiency and strong, efficient luminescence covering the 1.3-1.55 μm telecommunication window makes these nanoparticles promising materials in optical devices and telecommunications.
基金The work was supported by the National Natural Science Foundation of China (No. 29725410 and 29992530) and the 973Project (No. 2002CB613402).
文摘A new kind of polyfluorene containing oxadiazole as the side chain was synthesized. The introduction of oxadiazole moiety as more bulky group prevents the aggregation and reduces the crystallinity of the polymers. Efficient intramolecular energy transfer from oxadiazole moiety to the conjugated backbone has been realized, leading to 70% improvement of photoluminescence quantum efficiency of the designed polymers. Compared with PAF, the PFOXD exhibits significant improvement in electroluminescence properties, with luminous efficiency of 0.8 cd/A and maximum luminance of 1800 cd/m2.
