Design,Synthesis And Photovoltaic Properties Of The Methoxy Diphenylamine-based Hole Transporting Materrials For Efficient Perovskite Solar Cells

Perovskite solar cells have quickly become a powerful candidate for large-scale solar commercialization because they are less costly,easy to process and have now achieved 22.1% photoelectric conversion efficiency?PCE?.?N,N'-di-p-methoxyaniline?-9,9'-spirobifluorene?Spiro-OMeTAD?is usually used as a hole transporting material,and it is possible to effectively improve the Photoelectric conversion efficiency.However,its complex synthesis and multi-step purification make it costly and limit the potential of the material in manufacturing scale production.Therefore,it is particularly important to develop cost-effective hole transport materials with high efficiency and long stability.In this article,the following work is done:?1?In the third chapter,we use the carbazole as the central nucleus,through the Suzuki coupling reaction,Stille coupling reaction,C-N cross-coupling reaction were trisubstituted and tetra-substituted trimethoxy phenyl carbazole,thienyl carbazole and Methyldiphenylcarbazole?HTM1,HTM2,HTM3,HTM4,HTM5 and HTM6?have the appropriate HOMO level.In addition,the material has good stability,and the corresponding temperatures are 390.1 ?,367.3 ?,423.0 ?,389.6 ?,332.0 ? and 392.5 ? respectively when the weight loss is5%.Based on the above five kinds of small molecular materials?HTM1,HTM2,HTM3,HTM4,HTM5?as the hole transport material,the device of FTO / Sn O₂/ CH3NH3PbI3 / HTM / Au with typical planar configuration was prepared.Under the irradiation of AM 1.5G and power of 100 mW / cm2,The energy conversion efficiencies were 0.03%,0.04%,17.56%,0.02%,2.68%,respectively.?2?In the fourth chapter,we propose a new type of hole transporting material for PSCs 4,4'-dimethoxydiphenylamine-substituted spiro [3.3]heptane-2,6-difluorene?SDF-OMeTAD?.The synthetic pathway of SDF-OMeTAD requires only two steps from the start of the inexpensive starting material?Scheme 1?.Using the commercially available 2,7-dibromofluorene and pentaerythritol tetrabromide as starting materials,SDF-4Br was synthesized by one-step reaction and the center nuclei were obtained without purification by column chromatography.The target compound SDF-OMeTAD was then obtained using the palladium-catalyzed Buchwald-Hartwig C-N cross-coupling reaction.SDF-OMeTAD has good solubility in common organic solvents such as dichloromethane,chloroform,chlorobenzene and toluene,which is beneficial to solution processing.A typical planar structure device for FTO / SnO₂ /CH3NH3PbI3 / SDF-OMeTAD / Au was prepared with an optimum PCE of13.0% and an open circuit voltage of 1.10 V at 100 mW / cm2 AM 1.5 G lighting conditions.?3?In the fifth chapter,we synthesized three new synthetic hole transport materials,the central core were monofluorobenzene,difluorobenzene,dimethoxybenzene,respectively,by CN cross-coupling reaction to obtain two1-methoxy-diarylamine group,1FPh DPA,2FPhDPA,2OMePhDPA,respectively.The results show that the HOMO energy level is-5.28 eV,-5.20 eV and-5.21 eV,respectively,from the molecular structure,optical,thermal and electrochemical tests.These three new small molecular materials can be synthesized by one step,and the raw materials can be purchased directly.The reduced cost and less environmental impact are very promising for mass production.This is the development of perovskite solar cells Provided a reference.