The Fabrication And Intereface Modification Of Perovskite Solar Cells

As a new type of solar cell,perovskite solar cell has gradually become the aspirational pursuit of the researchers due to its advantages in high photoelectric conversion efficiency,low cost,simple process,and wet preparation.In recent years,the research on the perovskite solar cell has made a breakthrough,the photoelectric conversion efficiency has reached 22%,and the stability has also improved significantly.Process optimization and interface modification are two important means to improve the performance of perovskite solar cells.In this thesis,we studied the effects of the preparation process of perovskite solar cells on the micro structure and device performance of perovskite films,on this basis,we optimized the two-step preparation of perovskite films.Then PEO is used to modify the electron transport layer of PCBM,and analyzed its influence on the performance of the solar cells and the mechanism of action.First,we have explored and studied the preparation method of the device.It was found that changes in substrate preheating treatment,the rotational speed and concentration of each solution and the annealing temperature of perovskite can improve the crystallization and surface morphology of the active layer.After trying,we have found a way to prepare high-efficiency perovskite solar cells.In addition,the use of prefabricated layer optimization of the two-step method can effectively reduce the content of PbI2 in the perovskite film.When the current concentration of the solution is 0.2 mol/L,the content of PbI2 in the perovskite film is the least,the coverage is the highest,and the efficiency of the battery reaches 11.08%.Then,the modification effect and mechanism of PEO on the electron transport layer of PCBM were studied.The results show that the introduction of PEO modified layer can effectively improve the performance of the device.When the concentration of PEO solution was 2.5 mg/mL,the performance of the solar cells were optimal,and the short-circuit current density and photoelectric conversion efficiency were the highest,reaching 20.75 mA/cm2 and 13.8%,respectively.At the same time,the hysteresis of the solar cells is well suppressed.PEO-Modified Devices have less leakage current and reduce the device surface recombination.