Preparation And Interface Modification Of High Performance Perovskite Solar Cells

In recent years,perovskite solar cells?PSCs?have attracted enormous attention due to their excellent high efficiency,simple fabrication process,and low cost.Although the commercialization process of PSCs have been vigorously promoted so far,there are still many challenges and scientific issues to overcome.In which the preparing for high-quality perovskite films and then optimizing the films performance are particularly important.Based on these problems,this paper systematically carried out the research on regulating the nucleation and crystallization process of perovskite film,optimizing the interface performance via post-treatment and reducing the defect density in grain boundaries.In addition,we also study the stability of perovskite films and the preparation procedure for large-area devices and modules.The main research contents and results of this paper are summarized as follows:?1?We systematically studied the different annealing time and temperature to the influence of cesium-containing triple cation(FA_0.83MA_0.17)_1-xCs_xPb(I_0.9Br_0.1)₃perovskite.Then we proposed the high-temperature rapid annealing process.Based on this,we can get micron-sized large perovskite crystal with lower carrier recombination at the perovskite grain boundary.Also,the devices obtained the better performance with a lower concentration of trap state density.?2?We added an ionic liquid?IL?with the Lewis coordination function to the perovskite precursor solution.The nucleation rate and crystal growth process of perovskite can be adjusted by adding different amounts of ionic liquid additive,resulting in micron-sized large perovskite crystal.As a result,the best device can get a PCE of 21.32%and the stability of the device can reach over 500 h.?3?Black phosphorus quantum dots?BPQDs?with an average particle size of 2.83±0.63 nm was prepared by the liquid-phase ultrasonic stripping method.Then we used BPQDs as the post-treated layer on the surface of perovskite film.After treatment,the hole extraction ability of perovskite was enhanced and the enriched hole concentration at the surface was reduced,resulting in the improvement of the Voc and FF.As a result,the device got a PCE of 20.52%with the BPQDs post treatment.?4?We construct a carbonylate antioxidant capping layer atop the perovskite surface via solvent engineering method to prevent the oxygen permeation into perovskite layer during the fabrication process of the device to enlarge the oxygen region from 0.1 ppm to 100 ppm.Meanwhile,a pinhole-free perovskite film with large grain size,reduced Sn⁴⁺defects and long carrier recombination lifetime was fabricated.As a result,high-performance TPSCs could be achieved in a wide region of oxygen concentration with the power conversion efficiency?PCE?of 9.47%at 0.1 ppm oxygen and 9.03%at 100 ppm oxygen,respectively;the device was stable,maintaining over93%of its initial PCE after operating at the maximum power point under continuous light soaking(AM 1.5G,100 mW cm^-2)for 600 hours.?5?We combined the flash-vacuum method and high-temperature rapid annealing process together to prepare perovskite films.A large area and uniform perovskite film of 4×4 cm² and 10×10 cm² were successfully prepared.The series-parallel large-area perovskite module with an effective area of 16.96 cm² was assembled with a simple packaged way.As a result,under the standard AM 1.5G 100 mW/cm² illumination test,an open circuit voltage of 3.289 V,a short-circuit current of 80.25 mA and a maximum output power of 122.40 mW were obtained.Then we conducted a preliminary study on the application of large-area perovskite solar cells in the real environment.