Study On Synthesis And Photodetectection Properties Of Subphthalocyanine Compounds

The organic photodetectors based on organic semiconductors as active layers have the advantages of high sensitivity,fast response speed,and diverse device structure design.They have great application potential in national defense,environmental monitoring and other fields.Organic semiconductor materials have the advantages of low cost,many types,simple film formation process,easy modification of molecular structure,and large-scale application to flexible devices.In this dissertation,organic semiconductor materials with excellent photodetection performance are developed by modifying the peripheral and axial structures of chloroboro subphthalocyanine,and applied to organic photodetectors.In this paper,periphthalonitrile was used as the raw material to prepare peripheral unsubstituted subphthalocyanine,and then modified its structure by selecting eight types of phenol compounds with different p-substituent groups to prepare eight types of peripheral unsubstituted subphthalocyanine RPh O-Bsub Pc（H1-H8）.In addition,tetrafluorophthalonitrile was used as a precursor to prepare a peripherally modified perfluorosubphthalocyanine.And then eight types of phenolic compounds with different p-substituents were selected to modify the structure of the perfluorosubphthalocyanine.Eight kinds of perfluorosubphthalocyanine compounds RPhO-BsubPcF₁₂（H9-H16）were prepared.The molecular structure of the target compound was confirmed by means of infrared spectroscopy,mass spectrometry,and nuclear magnetic resonance spectroscopy.Their optical properties were tested by ultraviolet-visible spectrum and fluorescence emission spectrum;their electrochemical properties were studied by cyclic voltammetry;their thermal stability was analyzed by thermogravimetric curves.Photochemical tests show that the peripheral unsubstituted phthalocyanine compounds R-PhO-BsubPc（H1-H8）have UV-visible maximum absorption wavelength between555 and 565 nm;The maximum absorption wavelength of the peripheral fluorine-substituted perfluorosubphthalocyanine compounds R-PhO-BsubPcF₁₂（H9-H16）is between 565 and 575nm,indicating that the compounds have good absorption of green light.Electrochemical performance tests show that the HOMO level of the peripheral unsubstituted subphthalocyanine compounds（RPhO-BsubPc）is between-5.40 and-5.20 eV,while the LUMO level is between-3.99 and-3.73 eV;The HOMO level of the perfluorosubphthalocyanine compound(RPhO-BsubPcF₁₂)is between-5.50 and-5.27eV,and the LUMO level is between-4.24 and-4.00 eV.The thermal stability test shows that the T_d of RPhO-BsubPc（H1-H8）is between 215°C and 230°C,and the T_d of compounds RPhO-BsubPcF12（H9-H16）is between 240°C and 275°C,indicating that the compounds have good stability.NO₂PhO-BsubPcF₁₂ and NO₂PhO-BsubPc were selected as electron acceptor materials and donor materials respectively to prepare organic light detector.The device based on NO₂PhO-BsubPcF₁₂ has a response time of 22ms and 23ms,an optical responsivity of 14.1x10^-2 A/w,an external quantum efficiency EQE of 33.6%,and a specific detection rate of 15.76x10¹¹Jones.The devices based on NO₂PhO-BsubPc have response times of 27ms and 28ms,light responsivity of 1.75x10^-2 A/w,external quantum efficiency EQE of 4.17%,and specific detection rate equal to 1.52x10¹¹Jones,indicating that the subphthalocyanine series compounds have a good application prospect in organic photodetectors.