Synthesis And Photovoltaic Properties Of Thiophene[3,2-b]fluorene-based Hole Transport Materials

The world today faces two major problems of energy and the environment.Among them,solar energy has attracted attention because of its inexhaustible and inexhaustible energy supply,and solar cells that can convert light energy into electrical energy have also become key research projects.In recent years,perovskite solar cells have attracted wide attention due to their rapid development,simple manufacturing process and wide range of raw materials.As a important component of perovskite solar cells,hole transport layer composed of hole transport material is a hot research topic.Among them,linear,star-shaped and branched small-molecule hole transport materials have attracted wide attention due to their low cost.In most cases,the properties of the small molecule hole transporting material are closely related to the structure of the central core and significantly affect the hole mobility of the hole transporting material layer.It has been documented that strong intermolecularπ-πstacking is the key to improving hole mobility,and studies have shown that electron-rich fused heterocycles such as carbazole and benzo[1,2-b:3,4-b’:5,6-b"]Trithiophene is not only advantageous for p-p packing,but also for hole extraction.Therefore,it is very important to find a new electron-rich heterocyclic ring having a large P-extension.Therefore four kinds of thiophene[3,2-b]quinone small molecule hole transport materials,M107-M110,were synthesized by Suzuki coupling reaction.In this paper,the physicochemical properties and thermal stability of M107-M110 are characterized,such as UV fluorescence absorption spectrum,DPV curve and thermogravimetry,and differential thermal curve.And using a one-step anti-solvent method to use each small molecule for a hole transporting material,to fabricate a device having a composition consisting of tin oxyfluoride（FTO）/SnO₂+PCBM/perovskite/M107-110/Au,in order to be combined with thiophene[3,2-b]nucleus was compared to increase the small molecule hole transporting material X25having a carbazole nucleus.By comparing the performance of the device,it was found that the M109-based perovskite solar cell exhibited a high voltage of 1.11 V and an excellent photoelectric conversion efficiency of 18.14%.These results indicate that the thieno[3,2-b]indole derivatives are potential organic materials suitable for the design of hole transport materials.