Synthesis Of Organic Hole Transporting Materials For Perovskite Solar Cells

Organic small-molecule hole-transporting materials(HTM)of 11 were synthesized.Three HTMs based on truxene were obtained,and S14 shows high thermal stability and the best cell performance;four HTMs based on triphenylamine(TPA)were achieved,HBZ70 needs low-content to achieve its best cell performance,and the PCE was 4.53%;four HTMs based on diazosulfide were synthesized,which expands the absorption spectra of HTM successfully;different morphology of perovskite layer to study the relationship beteween HTM layer and perovskite layer,and the cell a PCE of reach 7.78%.Chapter one: briefly described the research background of PSCs,and introduced their schematic structure,working principle,evaluation parameters.Besides,the latest development of hole-transporting material was also reviewed.Bearing these in mind,the molecular design and research contents of this thesis were outlined.Chapter two: we reported a serie of truxene-based HTMs coded as S14-S15.For comparison,HTM S16 built on 1,3,5-tribromobenzene was prepared as a reference.The photophysical,electrochemical,thermal stability and photovoltaic properties of these HTMs had been systematically investigated.Device performance characteristics stated the truxene-based HTM name as S14 showed better performance than the other two HTMs.As a result,S14 as HTM for PSCs achieved a short-circuit photocurrent density(Jsc)of 8.03 m A cm–2,and power conversion efficiency(PCE)of 3.18% under the standard AM 1.5G illumination(100 mW cm–2).Chapter three: four new HTMs containing 2,2'-dihydroxybiphenyl and 1,1'-Bi(2-naphthol)were designed and synthesized,and incorporating carbazole unit into donor successfully.It is found that the HTMs that containing carbazole-group could notably retard the charge recombination,thus improving the cell performance.Furthermore,studied effect of different ratio of LiTFSI and TBP on the performance of PSCs.When the ratio of LiTFSI and TBP was 30 mM/120 mM,PSCs based on HTM HBZ70 displayed the highest PCE of 4.53%.Chapter four: developed four new HTMs(coded as BDZ1-4)featuring diazosulfide as core to form D-A-D system,for further expanding absorption spectrum and improving the cells performance.It can be found that incorporating diazosulfide unit as the core could efficiently broaden the light absorption.Besides,such HTMs displayed relatively good performance based on planar heterojunction cells,which had guided significance for our further study.Chapter five: Here,changed the proportion of Pb I2 and CH3NH3 Cl of “three-step” method for PSCs in order to get better cell performance.Besides,explored new preparation metods for PSCs based on “three-step” method.The proportion of Pb I2 and CH3NH3 Cl was 1:0.3 for PSCs based on “three-step” method displayed a promising conversion efficiency as high as 7.78% and study relationship beteween HTM layer and perovskite layer.