Research On 1D@3D Hybrid Perovskite Solar Cells

The efficiency of perovskite solar cells has been increased from 3.8%to 25.2%during the past decade,which indicates a great potential for their commercialization.At present,some companies have carried out pilot production of this kind of solar cell.The key problem that restricts commercialization is the stability of perovskite solar cell.Therefore,improving the stability of perovskite solar cells has been the top priority.The fundamental reason for the poor stability of perovskite solar cells is the unstable perovskite structure,which is sensitive to external conditions such as light,oxygen,water and high temperature.The sensitive conditions easily cause the negative ion migration,which accelerates the perovskite decomposition.The A-site cation of bipyridine in low-dimensional perovskite could enhance the interaction with halogen to inhibit the negative ion migration.In this scenario,the present thesis focuses on the structural regulation of perovskite materials and constructs a dimensional hybrid perovskite material to improve its stability.First,a new kind of perovskite material BPy-Pb I₂?I?with 1D skeleton structure was designed and fabricated.Through the dimensional hybrid strategy,we obtained the 1D@3D perovskite thin film.Then we further explored the kinetic process of the isomerization from BPy-Pb I₂?I?to BPy-Pb I₂?II?.Combined with the characterization results,we conducted in-depth studies on the film formation mechanism,matching mode of 1D@3D perovskite in the lattice heterojunction domain,carrier transport dynamics,ion migration dynamics,among others.Based on the above dimension hybrid structure,the defect states of perovskite films are effectively shielded,which accordingly gives rise to reduced electron and hole defect state concentrations as low as 1.43×10¹⁶cm^-3and6×10¹⁵cm^-3,respectively.Therefore the power conversion efficiency?PCE?of champion device reaches 21.18%,and the stability under sensitive conditions such as light,oxygen,water and high temperature are also significantly improved,especially under the conditions of water,light and oxygen,its stability is improved by 18 times compared with traditional perovskite solar cells.This paper provides a new kind of 1D@3D dimensional hybrid perovskite thin film,which achieves an excellent photovoltaic performance.This method provides a guidance for the efficient and stable solar cell devices?modules?preparation.It has important theoretical significance and commercial value for the research of cheap and environment-friendly photovoltaic technology,which is helpful to promote the development of Chinese new energy community.