Synthesis Of Perovskite-like Materials And Their Application In Solar Cells

Recently,a new type of non-toxic stable perovskite-like Cs₂SnX₆?X=I,Br?has attracted much attention.This material is not only non-toxic and stable,but also has excellent photoelectric properties.Therefore,this study chooses this material as the research object,aiming at its preparation,properties and application study.The main content is divided into the following points:Firstly,a new simple and efficient solution method has been proposed to synthesis the Cs₂SnI₆;and its properties have been studied by XRD,SEM,EDS and UV-vis.It was found that the as-synthesized Cs₂SnI₆ shows a black color with excellent light-absorbing ability and good environmental stability.Additionally,Cs₂SnI₆ can be stable in gamma-butyrolactone?GBL?but will decomposed in N,N-Dimethylformamide?DMF?.Secondly,the Cs₂SnI₆ has been applied in solid-state dye sensitized solor cell?DSSC?as a hole transmission material?HTM?,and a photoelectric conversion efficiency?PCE?about 1%has been obtained.The Cs₂SnI₆ has also been tried as a sensitizer in liquid electrolyte based DSSC.However,due to the instability of Cs₂SnI₆ in the electrolyte solution,the PCE was very small.Additionally,the Cs₂SnI₆ has been used as an acceptor in a thin film solar cell combining with a 9-vinylcarbazole?PVK?donor.Although photovoltaic property was detected,it is very small.Nevertheless,this proves the n-type characteristics of Cs₂SnI₆.Finally,a analogue of Cs₂SnI₆,Cs₂SnBr₆,has been synthesized and its properties bave been studied.Compared with the black Cs₂SnI₆,Cs₂SnBr₆ shows a light yellow color with good light-absorbing ability,though its absorption coefficient is lower than that of the former.Cs₂SnBr₆can be stable in dry air for more than 95 days and will not decompose below 180 ^oC,showing excellent environmental stability.Like Cs₂SnI₆,Cs₂SnBr₆ can be stable in GBL,but will decompose in DMF.