Efficient And Stable Large-area Wide-bandgap Perovskite Modules And Tandem Solar Cells

The power conversion efficiency（PCE）of perovskite solar cells（PSCs）has developed rapidly in the past decade,approaching the PCE of silicon solar cells.However,the PCE of single-junction PSCs is restricted by the Shockley-Queisser limit,which is difficult to overcome.The notorious stability of PSCs and large-area module manufacturing have brought great challenges for the progress of its commercialization.Combining PSCs and silicon solar cells to fabricate perovskite/silicon tandem solar cells is an efficient way to overcome the Shockley-Queisser limit.Therefore,development of efficient and stable large-area tandem solar cells is of great significance for the commercialization of PSCs in the future.In this thesis,we studied the process of fabrication of small-area PSCs and large area solar modules by carefully optimization of the perovskite composition and interfacial properties.In addition,transparent electrode was used to fabricate semitransparent solar cells,which were coupled with silicon solar cells to fabricate 4-terminal（4-T）perovskite/silicon tandem solar cells.Such efforts have provided theoretical basis and practical experience for achieving highly efficient and stable large-area 4-T perovskite/silicon tandem solar cells.The main research conclusions and innovations are summarized as follows:（1）In order to manufacture perovskite/silicon tandem solar cells,the bandgap of top perovskite solar cells was firstly selected.After adjusting the Br content of FA_0.8Cs_0.2Pb(I_xBr_1-x)₃,it was found that the bandgap of perovskite containing 20%Br component was 1.67 e V,which met the bandgap requirement of perovskite/silicon tandem solar cells.The surface treatment of FA_0.8Cs_0.2Pb(I_0.80Br_0.20)₃ perovskite with phenethylamine hydroiodide（PEAI）or hexadecyltrimethylammonium bromide（HTAB）organic ammonium salt resulted in an improvement of the device performance,and HTAB surface treatment PSCs achieves 17.8%steady-state output efficiency（SPO）.（2）The effect of organic ammonium salt phenyltrimethylammonium bromide（PTABr）surface treatment on FA_0.8Cs_0.2Pb(I_0.80Br_0.20)₃ on their photovoltaic performance and stability are studied.Firstly,the influence of PTABr concentration on the properties of perovskite film and its PSCs performance was studied.it was found that 1 mg/m L PTABr surface treatment of perovskite films can obtain the champion photovoltaic performance,the SPO of 18.8%.Studies have shown that PTABr can passivate the film defects by compensating the bromine ions escaped by perovskite films during annealing.Subsequently,this method was applied to the surface treatment of large-area perovskite thin films to fabricate large-area perovskite solar modules with active area of 10 cm² and SPO of 15.2%.After PTABr surface treatment,the module can maintain 81%of the initial efficiency after 1000 h aging,which is greatly improved compared with the untreated module.（3）Four-terminal tandem solar cells based on FA_0.8Cs_0.2Pb(I_0.80Br_0.20)₃ perovskite was fabricated.By replacing the top electrode of perovskite solar cells with transparent electrode,transparent perovskite solar cells based on wide bandgap perovskite were fabricated,and 16.0%PCE was achieved.The PCE of large area semitransparent module was 7.0%.Semitransparent cells and silicon solar cells were coupled into 4-T perovskite/silicon tandem solar cells and obtained 25.0%PCE.