| Both the survival of human and the development of society depend on the use of energy.Nowadays,80%energy we use is traditional fossil fuels,but the depletion of fossil fuels has seriously constrained the rapid development of human society.The global energy crisis has become a human consensus.Exploiting green renewable energy is the most effective way to solve the energy crisis.Among all of the renewable energy,solar energy becomes the most promising new energy because of widely distributed,unlimited reserves and environment-friendly.Commercialized silicon solar cells have a great breakthrough in the photovoltaic performance,but the further practical application is limited by the high costs.Recently,perovskite solar cells(PSCs)have drawn tremendous interests because of its low costs and good photovoltaic performance.The photoelectric conversion efficiency of PSCs has increased from 3.8%in 2009 to 2016 Year of 22.1%.However,the commercialization of PSC is still constrained by lots of problems such as low reproducibility,poor stability and severe hysteresis.There are many strategies to solve these problems,such as optimizing film morphology and interface properties.In this paper,the first work is to propose a new NiO thin film preparation method(vapor deposition method)to optimize the morphology of NiO film,and thus improve the charge transmission characteristics and as a result of enhancing the device photovoltaic performance.The second work is to regulate the growth of the perovskite crystal and the interface electron coupling through the self-assembly of modified ZnO surface,and then enhance the charge transfer and transfer characteristics to improve the photovoltaic performance of PSCs.The results are as follows:1.A method for vapor deposition of high quality NiO thin films was reported.A dense,flat NiO thin film was prepared by depositing a pre-layer of metal Ni on the substrate followed by high-temperature calcination oxidation,which had good p-type semiconductor properties.Compared with the the NiO film prepared by spin coating,the NiO pores of the vapor deposition are obviously reduced and the roughness is greatly reduced.The NiO/Perovskite/PCBM/Ag structure of PSCs is more favorable for the extraction of holes by NiO and promotes efficient charge separation with transmission.The PCE up to 14.88%was obtained by vapor deposition NiO,which was higher than that of PSCs(13.07%)based on NiO prepared by spin-coating method.At the same time,the power conversion efficiency of large size PSCs with integrated area of 1.0 cm2 can achieve to 12.79%,which are obviously better than PSCs(8.79%)based on spin coating.This work provides a new solution for the preparation of uniform and dense NiO films.2.Based on the ZnO/Perovskite/Spiro-MeOTAD/Ag structure,the purpose of the modified ZnO was obtained by the order of molecular self-assembly of p-aminobenzoic acid(PABA)on the ZnO surface.The dipole orientation of the modified ZnO surface is reduced from 3.69 eV to 3.47 eV by the dipole orientation of PABA and has a larger surface energy.The low surface work leads to the formation of a high open circuit voltage(VOC= 1.16 V),while the high surface energy and amino can be well regulated by the perovskite crystal growth,thereby enhancing the crystallinity of the perovskite film,particle size and reducing porosity.The photoelectric conversion efficiency of the device based on the modified ZnO is 16.55%,which is better than that of the device based on the blank ZnO(13.66%).In addition,the device integrated on the PET flexible substrate can achieve 15.16%photoelectric conversion efficiency,and after 800 bending can still maintain the initial test efficiency of 80%or more. |
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