Sandwich Type Metal Phthalocyanine/porphyrin Material Preparation And Performance Study On Low Power Upconversion

Triplet-Triplet annihilation upconversion（TTA-UC）is known that materials absorb low energy light（long wavelength）,but emit high energy light（short wavelength）.It only needs low energy exciting light（such as the intensity of sunlight）,this feature brings potential applications in the solar energy application（organic photovoltaic,light catalysis）and on ultra-weak bioluminescence（fluorescence microscopy,biological imaging）and so on.Now,the researches in TTA-UC materialsThe main work of this paper:1.The synthesis of materials: In order to realize the diversity of sensitizers and to improve the performance of upconversion,we synthesized a series of multilayer heavy metal platinum and palladium phthalocyanine / porphyrin complexes,respectively named PtPc₂,PdPc₂,Pd₂Pc₃,Pt（MeTPP）₂,Pd（MeTPP）₂.These materials are used as the sensitizers of upconversion system.PtPc₂,PdPc₂,Pd₂Pc₃ mainly improved the dissolution of phthalocyanine materials,and they respectively improve the phthalocyanine / porphyrin material of triplet phosphorescence lifetime and so on.2.How the structure of sensitizers affect the performance of upconversion: Our system compares the different center metal and different spatial layer of phthalocyanine / porphyrin sensitizers on upconversion.When phthalocyanine ligand act as sensitizers,and Rubrene as acceptor,in consideration of the strength and the efficiency,it is concluded that: Pd₂Pc₃（300、0.64 %）>PdPc₂（220、0.58 %）>PtPc₂（125、0.42 %）.When porphyrins ligand act as sensitizers,and DPA as acceptor,it comes out: Pt（MeTPP）₂（3200、13.5 %）> PtMeTPP（1800、18.5 %）;Pd（MeTPP）₂（9100、21.8 %）> PdMeTPP（6900、29 %）.Consider the regularity of both phthalocyanine and porphyrin,we conclude that metal Pd works better than the metal platinum ligand sensitizers on the performance of upconversion.When we consider the molecular structures,it can be concluded that the more spatial structure layers of the sensitizers,the longer life times of phosphor,and higher triplet energy levels they have.Finally,in the upconversion performance,the more spatial structure layers of the sensitizers,the better intensity and efficiency of the upconversion fluorescence.3.A new medium of TTA upconversion: We used O/W microemulsion medium as the solvent of two-component system.And we solved the decomposition of Rubrene when it is under light and oxygen.What’s more,we solved the problem of deoxygenization of the upconversion two-component system.Compared to the toluene as solvent,under strong light and oxygen environment for two hours,the concentration of rubrene almost does not reduce,the upconversion fluorescence efficiency also keep a high value.