Preparation Of Green And Flexible Organic Solar Cells Using An Interfacial Layer Of A Perylene Diimide Derivative PDIN

Compared with silicon-based solar cells and inorganic semiconductor thin-film solar cells,organic solar cells use organic materials as light-absorbing layers,which are most suitable for flexible devices and have broad application prospects in flexible and wearable optoelectronic devices.The main difference between flexible devices and rigid devices has always been the mechanical properties of the bottom transparent electrode,and obtaining a high-performance flexible bottom electrode is the key to improving the photovoltaic performance of flexible devices.Although the energy conversion efficiency of organic solar cell devices has improved rapidly in recent years,these high-efficiency small-area organic solar cells are almost all fabricated by spin-coating using harmful halogenated solvents,which is difficult to meet future commercial mass production requirements.This thesis provides a low-cost,easy-to-process,high-performance flexible composite electrode preparation method,which is suitable for the active layer systems prepared by both traditional halogen-containing solvents and non-halogen solvents,and obtains high-efficiency flexible organic solar cells using green solvent.The main research contents of this thesis are as follows:(1)We used the high-performance PM6:Y6 system as the active layer in this part.Then the cathode interface material(PDIN)suitable for the high-performance active layer system was selected from the representative cathode interface materials(PDIN,PDINO,Zn O,NDIN).To well combine PDIN with flexible electrodes PET/Ag NWs for the deficiencies of PET/Ag NWs flexible electrodes and obtain high performance,the interfacial contact was optimized from the aspects of Plasma duration,PDIN solution concentration,spin coating speed,acetic acid addition,annealing temperature and duration,etc..The performance of PET/Ag NWs/PDIN flexible composite electrodes was combined with different high-performance active layer systems to prepare flexible devices and explore the universality of flexible composite electrodes.(2)Using xylene and toluene as active layer solvents,respectively,the donor polymer PBDT-QW was blended with the small molecule acceptor Y6 to prepare rigid BHJ-structured devices.By optimizing the morphology of the active layer,the optimal process of PBDT-QW:Y6was explored,and a high-performance organic solar cell based on the PBDT-QW:Y6 system was obtained.The device using xylene as the active layer solvent exhibits a high energy conversion efficiency of 11.22%.This work d Jscovers an active layer system based on non-halogenated solvents,which is beneficial to the industrialization of organic solar cells.(3)Combining the PET/Ag NWs/PDIN flexible composite electrode with the xylene-based PBDT-QW:Y6 active layer system,a flexible device with a device structure of PET/Ag NWs/PDIN/PBDT-QW:Y6/Mo O₃/Ag was prepared.The green high-efficiency flexible device with a power conversion efficiency of 7.35%was obtained and then subjected to a bending test.When the bending radius was 5 mm,the energy conversion efficiency could still remain above 70%of the initial value after bending for 150 times.