Regulation On Perovskite Film Quality And Research On Photovoltaic Performance By Hot Imprint Procedure

In the past decade,perovskites solar cells(PSCs)have drawn monumental attention by researchers due to outstanding photovoltaic performance.As the most promising photovoltaic material,the certification efficiency of PSCs has exceeded25%.However,perovskite films are susceptible to the extrinsic factors,such as water,oxygen,and light,which may cause a bad device performance.And it is the primary problem that hinders its sustainable development and commercial application.Polycrystalline perovskite films generally have high-density defects due to the numerous crystal nucleus and small grains in the film formation.These defects are commonly regarded as the source of non-radiative recombination,which seriously damage the photovoltaic performance of PSCs.So,the quality of the light absorbing layer based on the PSCs is vitally important for the performance and stability.In order to achieve the purpose of optimizing the film quality,we introduced a new method to prepare high-quality perovskite films with appropriate grain size in this paper,which was of great significance for the development of high-performance PSCs.High-quality perovskite film is an essential prerequisite for high-performance PSCs.We have introduced planar imprint(Pi P)to promote perovskite film recrystallization,and high-quality perovskite film was obtained with large grain and ultra-smooth surface.Moreover,hydrophobic trimethoxy(1H,1H,2H,2Hheptadecafluorodecyl)silane(FAS)oligomers were introduced to films surface as bifunctional barrier to passivate the defects and protect the perovskite film.The power conversion efficiency(PCE)of Pi P treated PSCs was increased from 18.35%to 20.52%.And due to the reduction of grain boundary and the positive effect of FAS oligomers layer,the optimized device showed higher moisture resistance.Owing to the poor light absorption and restricted charge transport,twodimensional(2D)perovskite solar cells show the inferior PCE,limiting their applications as photovoltaic material.To address these challenges,a strategy was proposed to develop high-quality patterned 2D perovskite through patterned imprint for efficient PSCs.In the patterned imprint process,the recrystallization happened in2 D perovskite films,which motivated high n-phase for better carrier separation and transportation under directional compressive stress of template.Especially,regularly arranged cylinder patterns are favorable for better light absorption and increased interfacial contact.Eventually,the PSCs based on patterned 2D perovskite film exhibit higher PCE of up to 18.10% as well as improved general stability.