Design,Synthesis Of Ployindoles-based Hole Transporting Materials For Efficient Perovskite Solar Cells

Developing excellent hole transporting materials(HTMs)is one of the significant strategies to improve the photoelectric conversion efficiency(PCE)and stability of the perovskite solar cells(PSCs).Nowadays,the most widely used HTMs is Spiro-OMe TAD.However,the complex synthesis route and high cost of Spiro-OMe TAD limited the commercialization of perovskite solar cells.Therefore,designing and prefabricating novel cheap and easily available HTMs with higherperformance is one of the hotspots of research in PSCs.During this process,reasonable molecular design may make a contribution to expolder the HTMs with higher-performance by less resource in a shorter period of time.This paper is going to be aimed to research the influences of the photoelectric property on the modified group and core framework of HTMs,which can provide useful routes and messages to design and prepare the high-performance HTMs.Main research contents are followings as bellows:(1)We design and synthetize a series of small molecule HTMs(T1,T2 and T3)based on the triazatruxene(TAT)as the core and the diphenylamine(DPA)derivatives.Through changing the number of methoxyl groups on the modified group of DPA,we effectively regulate the photoelectric property of these materials.Furthermore,we apply these materials as hole transporting layer(HTL)for PSCs.The effects of methoxy groups on the photoelectric properties of HTMs and the performance parameters of PSCs provide reference informations to design and develop new HTMs.(2)Based on the TAT as the core we design and synthetize a series of small molecule HTMs(T4 and T5)by change the modified groups.Moreover,we research the effects of different molecular structures on the photoelectric properties of materials,which can help us to filter as the more reasonable molecular frame of HTMs.(3)We design and synthetize a series of small molecule HTMs(D1,D2 and D3)based on the diindolotriazatruxene(DIT)as the core.DIT processes expanded two-dimensional ?-conjugation system and strong electron donating ability,meanwhile,it can be prepared by the simple one-pot way.Therefore,we chose it as the core of HTMs,and use the excellent performance materials which were discussed in the preceding paragraphs as the modified groups to regulate the photoelectric properties of these materials.It is found that the DIT derivatives have lower HOMO energy level and excellent hole mobility through the systematic study,which demonstrates these materials have great potential for efficiency PSCs.