Synthesis And Properties Of Chrysenedithiophene And Their Application In Supermolecular Self-assembly And Organic Solar Cells

During the past decades,organic semiconductor materials has been wide applied in the fields of organic light emitting diodes,organic thin film transistors,organic photovoltaic devices,and bioimaging and sensing has promoted the development of organic electronics.The major advantages of organic semiconductors are including their light-weight,low-cost,flexibility and feasibility for solution-processed devices.Especially,a large pool of small molecular and polymeric semiconductors have been developed by rationalized molecular engineering principles.For example,by extending the conjugation length,controlling the planarity and tuning the energy levels,the performance of the corresponding devices has been improved significantly.The mobility of solution-processed organic field-effect transistors based on D-A polymers reached 20 cm~2/Vs.The power conversion efficiency of organic solar cells based on polymer donors and non-fullerene accepotrs has been higher than 14%.As well-known that the organic semiconductors based on BDT and NDT displayed impressive performance in OFETs and OPVs,due to their planarity and extended conjugation length.have already been reported in the last few years.Extending a linear conjugation along its vertical direction to form a two-dimensional conjugated system is a rational design to enhance?-?interaction and absorption ability.Employing such molecular engineering has successfully led to high-performance polymer solar cells.Further extend the?-conjugation on the basis of NDT3 and NDT4 by fusing two alkoxy benzene to achiveed?ChDT and?ChDT.The basic characterics of?ChDT and?ChDT and the corresponding conjucted polymers performance in photovoltaic devices were studied in this paper.The content of this thesis is roughly divide into two parts.In the first part,the design and synthesis of?ChDT and?ChDT were described.Interestingly it was found that both?ChDT and?ChDT exhibit nanplanar conjugated system according to the the theoretical calculations and the analysis of their single crystals.It is speculated that the nonplanar structures is caused by the strain in the molecular subunits severely distorts the aromatic system away from their planarity.The concave surfaces of these contorted molecules can form ideal receptors for molecular recognitions and assembly with spherical molecules such as fullerenes.The supermolecular assembly of these two contorted molecules with fullerenes in solutions in condensed states were both investigated by UV-vis absorption,fluorescence titrations,DSC analysis,SEM and TEM measurments.Part Two,two conjugated polymers based on?ChDT and benzothiadiazole acceptors were designed and synthesized.After the investigation of their physical properties,the corresponding OPV devices were fabricated and characterized.Preliminarily,the PCE of polymers of?ChDT-DTORBT reached to 4.16%with high open circuit voltage of 0.86 eV.The interaction between PCBM71 and?ChDT-DTORBT dominated the micro-morphology of the active layers.Further investigation on this point will facilitate the device performance improved.In summary,we developed a family of contorted building blocks of?ChDT and?ChDT.The synthetic method and their fundamental properties were investigated in detail.The potential in constructing conjugated polymers as electron-donating unit was also indentified.It is believe that?ChDT can arouse widely interesting in the community of organic semiconductors and organic electronics...