Synthesis Of Nonlinear Conjugation Hole Transport Materials For Inverted Perovskite Solar Cells

Nowadays,the world is faced with two major crisis of energy shortage and environmental pollution.The development and utilization of new energy has always been the goal of researchers However,as an inexhaustible energy source,solar energy has attracted scientists'attention.In recent years,perovskite solar cells?PSCs?have emerged as a new force in the photovoltaic field.Within a few years,the photoelectric conversion efficiency?PCE?has exceeded 20%.The hole transport layer is the key component of it,which has undoubtedly become a hot topic for human exploration.Several novel organic small molecules were designed and synthesized to replace PEDOT:PSS as a hole transport material?HTMs?for inverted perovskite solar cells?i-PSCs?,and the photovoltaic performance of the corresponding devices was studied in depth.We have synthesized two non-linear molecules with Y-shaped?XSln847?and X-shaped?XSln1453?structures via a facile synthetic route,The intermediate and target products were tested by NMR,IR and MS.XSln847 single crystal was obtained by optimizing the proportion of mixed solvents.According to x-single crystal diffraction analysis,the molecule has a strong?-?interaction,forming a“nest”structure within the molecule,thereby demonstrating a higher hole transfer ability.Two hole transport materials were applied to i-PSCs.Current-voltage?J-V?test showed that the device based on XSln847 reveal excellent electrical conductivity and hole transmission ability without doping?Li-TFSI and TBP?,affords a higher power conversion efficiency?PCE?of 15.02%,with an open circuit voltage of 1.06Vand a short circuit current of 21.58mA/cm^-2.What's more,The efficiency is further improved to17.16%when using XSln847 doping with 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinodimethane?F₄TCNQ?,which is much higher than that of the widely-used PEDOT:PSS?PCE=11.95%?when measured under the same condition.In order to further explore the relationship between the molecular structure of hole transport materials and the photovoltaic performance of devices,This paper also designed and synthesized containing-CN/-CF₃ and other electron-absorbing groups triarylamine hole transport materials G161-G164 and G171-G173.The intermediates and target products were characterized by NMR hydrogen spectrum and carbon spectrum.The preparation of devices and the test of photovoltaic performance need to be further studied.