Application Of Zn-Al LDHs Pyrolysis Products In 2D/3D Hybrid Perovskite Solar Cells

Organic-inorganic hybrid perovskites are very promising light absorbers for next-generation photovoltaic devices due to their low-cost solution manufacturing process and high efficiency.Three-dimensional(3D)perovskites have good light absorption,but humidity stability.Two-dimensional(2D)perovskite has good humidity stability,but poor conductivity and narrow light absorption.The 2D/3D stacking structures can combine the advantages of enhanced stability in 2D perovskite and the advantages of strong light absorption in 3D perovskite materials,which has become a research hotspot in recent years.Because there are few studies on the influence of 2D/3D hybrid perovskite morphology on the performance of perovskite solar cells,therefore,the effect of 2D/3D hybrid perovskite morphology on the performance of solar cells was investigated by spin-coating different concentrations of BA in chlorobenzene solution.In recent years,composite metal oxides have been extensively studied in dye-sensitized solar cells,fuel cells,and quantum dot sensitized solar cells.MMO can also be prepared after high temperature pyrolysis of layered double hydroxides(LDHs).The MMO prepared by the method has the characteristics of uniform doping of metal elements and adjustable doping amount of metal elements.Therefore,Zn-Al MMO was prepared by Zn-AL LDHs and applied to 2D/3D hybrid perovskite solar cells as electron transport layer.The specific operations are as follows:(1)Firstly,the 3D perovskite precursor solution was spin-coated by one-step method.By optimizing the concentration of the precursor solution,the best performance 3D perovskite solar cell was prepared.When the concentration of the 3D perovskite precursor solution was 1.5 mol L-1.The performance of the C-based device is the best with an efficiency of 8.73%.Next,different concentrations of n-butylamine(BA)chlorobenzene solution were spin-coated on the best performing 3D perovskite film to form a thin 2D hybrid perovskite layer on the 3D hybrid perovskite layer.When the solution concentration of BA was found to be 3%v/v,the performance of the device was the best,and the efficiency was 9.01%.2D/3D solar cells not only have improved performance compared to 3D perovskite solar cells,but also have long-term stability.(2)Different ratios of Zn-Al LDHs were prepared by double-drop co-precipitation method,and LDHs were calcined at different temperatures to prepare Zn-Al MMO,which was applied to 2D/3D hybrid perovskite solar cells as electron transport layer.The effect of metal element ratio and calcination temperature on device performance was also investigated.Finally,when the annealing temperature is 600?and Zn2+/Al3+is 5,the performance of the device is best,and the optimal photoelectric conversion efficiency was 6.75%.Compared with pure ZnO-based device,the performance and stability of Zn-Al MMO-based devices have increased.