VISIBLE photoluminescence (PL) from nanostructured group Ⅳ semiconductors has attractedgreat attention, since visible PL at room temperature(RT) from porous silicon was discoveredby Canham in 1990. This makes it poss...VISIBLE photoluminescence (PL) from nanostructured group Ⅳ semiconductors has attractedgreat attention, since visible PL at room temperature(RT) from porous silicon was discoveredby Canham in 1990. This makes it possible that the conventional planar technology of sili-con may be used in optoelectronics devices directly. Moreover, it is also an ideal object展开更多
A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy...A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy）phenyl]- 9H-fluorene. The structure and properties of the polymer are characterized and evaluated by NMR, IR, UV, PL and TGA analyses. The polymer is soluble in common organic solvents, possesses high thermal stability （Td 〉 330℃）, and emits a strong blue light of 465 nm in both solution and solid states.展开更多
Electrogenerated chemiluminescence(ECL)has been extensively used in ultrasensitive electroanalysis because it can be generated electrochemically without using expensive optics and light sources.Visible ECL emission ca...Electrogenerated chemiluminescence(ECL)has been extensively used in ultrasensitive electroanalysis because it can be generated electrochemically without using expensive optics and light sources.Visible ECL emission can be obtained with a reasonable quantum yield and stability.Blue ECL is rare and often suffers from stability and poor quantum efficiency.Blue ECL emission at 473 nm from organometallic halide perovskite nanocrystals(PNCs),CH_(3)NH_(3)PbCl_(1.08)Br_(1.92),is reported here for the first time using tripropylamine(TPrA)as co-reactant.The blue ECL emission peak resembles its photoluminescence peak position.In addition to this blue emission peak,the ECL spectra of CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs also showed a broad ECL peak at 745 nm.Generation of the second ECL peak at 745 nm from CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs was can be explained by the existence of surface trap states on as-synthesized PNC due to incomplete surface passivation.Halide anion tunability of ECL emission from CH3NH3PbX3(X:Cl,Br,I)PNCs is also demonstrated.The fluorescence microscopy image of single PNC and stability of selected single PNCs are presented in this with simultaneous acquisition of fluorescence spectra using 405-nm laser excitation.The photoluminescence(PL)decay was described by PL lifetime(τ)of 1.2 ns.The effect of the addition of surfactants(oleic acid and n-octylamine)on the fluorescence intensity and stability of CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs is also discussed.展开更多
文摘VISIBLE photoluminescence (PL) from nanostructured group Ⅳ semiconductors has attractedgreat attention, since visible PL at room temperature(RT) from porous silicon was discoveredby Canham in 1990. This makes it possible that the conventional planar technology of sili-con may be used in optoelectronics devices directly. Moreover, it is also an ideal object
基金This project was supported in part by the Research Grants Council of Hong Kong Special Administrative Region,China(Nos.603304,604903,N_HKUST606_03,and HKUST6085/02P)the University Grants Committee of Hong Kong via an Area of Excellence(AoE)Scheme(AoE/P-10/01-1-A).
文摘A hyperbranched poly（aryleneethynylene） containing anthracene chromophore was synthesized by palladiumcatalyzed cross-coupling reaction of 2,4,6-triiodophenyl 9-anthracenylcarboxylate with 9,9-bis[4-（2-propynyloxy）phenyl]- 9H-fluorene. The structure and properties of the polymer are characterized and evaluated by NMR, IR, UV, PL and TGA analyses. The polymer is soluble in common organic solvents, possesses high thermal stability （Td 〉 330℃）, and emits a strong blue light of 465 nm in both solution and solid states.
基金We would like to thank the financial support from the National Science Foundation(NSF award CHE 1508192 and OIA-1539035).
文摘Electrogenerated chemiluminescence(ECL)has been extensively used in ultrasensitive electroanalysis because it can be generated electrochemically without using expensive optics and light sources.Visible ECL emission can be obtained with a reasonable quantum yield and stability.Blue ECL is rare and often suffers from stability and poor quantum efficiency.Blue ECL emission at 473 nm from organometallic halide perovskite nanocrystals(PNCs),CH_(3)NH_(3)PbCl_(1.08)Br_(1.92),is reported here for the first time using tripropylamine(TPrA)as co-reactant.The blue ECL emission peak resembles its photoluminescence peak position.In addition to this blue emission peak,the ECL spectra of CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs also showed a broad ECL peak at 745 nm.Generation of the second ECL peak at 745 nm from CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs was can be explained by the existence of surface trap states on as-synthesized PNC due to incomplete surface passivation.Halide anion tunability of ECL emission from CH3NH3PbX3(X:Cl,Br,I)PNCs is also demonstrated.The fluorescence microscopy image of single PNC and stability of selected single PNCs are presented in this with simultaneous acquisition of fluorescence spectra using 405-nm laser excitation.The photoluminescence(PL)decay was described by PL lifetime(τ)of 1.2 ns.The effect of the addition of surfactants(oleic acid and n-octylamine)on the fluorescence intensity and stability of CH_(3)NH_(3)PbCl_(1.08)Br_(1.92) PNCs is also discussed.
