| The main contribution of this paper is at exploring Star-Shaped acceptor materials and hyperbranched receptor materials,they are non fullerene acceptor material,can be used in organic solar cells.This paper discusses the structure and properties of the compounds.Compared to linear materials,star-shaped materials have many advantages.They can effectively reduce intermolecular packing and reduce cross-linking effects.After the film is prepared,the photoelectric properties of the star-shaped material have been greatly improved compared to the linear material.Polymers have relatively few reports due to their complex synthetic routes and difficulties in purification and solubility.The small molecular acceptor material has a definite molecular weight,is easy to purify,has a clear synthesis method,and has a variety of structures and can be matched with different donor materials,thus more interests are focused on the small-molecule acceptors.In this paper,a series of star-shaped small molecule receptors and hyperbranched polymer receptor with truxene as the core were synthesized.The solar cell device was prepared by blending with the donor PBDB-T to explore the photovoltaic performance of the star receptor material.The main research work is as follows:1.Firstly four(2,7,12)-tribromotrimeric fluorenes(A-Cn-1)with different alkyl side chains were synthesized.They were used as starting materials,a series of star-shaped small molecule receptors A-C6,A-C8,A-C10 and A-C12 were synthesized by Suzuki coupling reaction.All of these four compounds are dark purple,and the solubility in common solvents such as dichloromethane and tetrahydrofuran becomes better as the carbon chain grows.The UV-visible absorption spectra of the four compounds were measured and the results showed that the four compounds showed similar absorption spectra in solution and film.The absorption peak in the film has a red shift compared to the solution,this is Because the compound formed agglomerates in the film.TGA test results show that the four receptor molecules have good thermal stability,the thermal decomposition temperature of A-C6 is275 ?,and the thermal decomposition temperatures of A-C8,A-C10 and A-C12 are all305 ?.Receptor molecules all exhibit 5% mass loss at 355 ?,they all meet the basic requirements for device operation.The electrochemical properties test showed that the four receptor molecules all have suitable HOMO and LUMO energy levels,which can provide acertain driving force for the separation of excitons and effectively separate the excitons into free charges.Organic solar cell devices were prepared using polymer PBDB-T as a donor material.The test results show that four compounds have high power conversion efficiency(PCE).A-C10 is good due to its good solubility,aggregation behavior,and good blend film,the topography has the highest energy conversion efficiency,reaching 5.17%.2.A hyperbranched polymer receptor W based on truxene was designed and synthesized,with 5,5,10,10,15,15-sixty-twelve alkyl-2,7,12-three bromide truxene(A-C12-1)and2,5-bis(trimethylstannyl)thieno[3,2-b]thiophene as raw materials by Stille coupling to obtain a suitable molecular weight of polymer M,capped with 5-formyl-2-thiopheneboronic acid and3-(dicyanomethylidene)indan-1-one(INCN)gives polymer W.The molecular structure was verified by a FTIR.Polymer W has good solubility and can be dissolved in common solvents such as chloroform,toluene,tetrahydrofuran and the like.Polymer W has a very high UV absorbance in both solution and film,and the absorption peak in the film due to aggregation behavior produces a red shift compared to the solution.Polymer W has good thermal stability and suitable energy levels,and can be well matched to donor materials.The energy conversion efficiency of the battery device based on PBDB-T:W reached 0.26%. |
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