Fabrication And Application Of Broad Bandgap High Efficiency Perovkite Solar Cells

In recent years,organic-inorganic hybrid perovskite solar cells have been attracted a large number of researchers all around the world by the advantages of their large optical absorption coefficient,tunable bandgap and easily fabricated process.The power conversion efficiency of perovskite solar cells in the laboratory increased from3.8%in 2009 to 24.2%in 2019.At the same time,the adjustable energy band structure provides a possible for the development of tandem solar cells.In addition,perovskite has distinctive advantages in photoelectric detection,luminescence and other fields,showing great commercial value.On the one hand,the performance of perovskite solar cells depends on the quality of perovskite films,and the quality of perovskite films is related to the crystallization process during perovskite fabrication.On the other hand,the defects density in perovskite film can also decrease the performance of perovskite solar cells.Therefore,this paper mainly introduces three aspects about perovskite solar cells:1.High-efficiency perovskite solar cells were prepared by one-step spin-coating process by antisolvent-assisted crystallization.I have changed the ratio of dimethylformamide(DMF)and dimethyl sulfoxide(DMSO)in perovskite precursor solution to regulate the crystallization process of perovskite effectively,and the surface morphology of the films and the crystallinity of perovskite crystals was improved.2.We adding different concentrations as additives in perovskite precursor solution to passivate the cationic vacancy defects and halogen anion vacancy defects in perovskite films.It is found that K~+can enter perovskite crystals and slightly change the crystal structure of perovskite,leading to the red shift of PL peak and absorption edge.At the same time,with the increase of doping concentration,the grain size and the absorption coefficient increasing obviously.The performance parameters of the device are analyzed.When the doping concentration of KI is 8%,the passivation effect is the best.The open circuit voltage of the device is 1.19 V,the short circuit current density is 19.62 mA/cm~2,the filling factor is 77.72%,and the energy conversion efficiency is 18.04%.3.Broadband gap perovskite is often used in tandem solar cells.We have prepared semitransparent perovskite solar cells by replacing opaque Au electrodes with transparent ITO electrodes.The tandem solar cells can be stacked with other narrow bandgap solar cells simply.In the presence of buffer layer,the average efficiency of simitransparent perovskite solar cells reaches 11.41%,the best PCE is 12.36%.laying a foundation for the future efficient stacked solar cells.