The Preparation Of Planar Heterojunction Perovskite Solar Cells And Study On Characteristics Of Fe’s Doping

In recent years,Perovskite Solar Cells add a bit of color to the industry.There are many kinds of the perovskite solar cells.Such as: planar heterojunction perovskite solar cells、No hole transport layer solar cells、mesoporous-planar hybrid structure perovskite solar cells and so on.N-i-p planar structure perovskite solar cells is simpler and more flexible,which provides the possibility for the development of laminated solar cells,it has become the focus of attention.The performance of the device is related to the morphology and quality of the perovskite films,therefore,it is very important to prepare high quality perovskite films.At the same time,with the further development of perovskite solar cells,they become industrial and commercialization,and lead pollution problems also aroused people’s attention.In this paper,the quality of the film was improved by regulating the morphology and concentration of the perovskite film,and the effect of Fe2+ doping on the properties of the films was studied preliminarily.The following is the main content:（1）The film-forming properties of perovskite films were studied by controlling the dropping time of anti-solvent by one-step spin coating method.In the experiment,chlorobenzene as anti-solvent,high-speed spin-coating time is 25 s.The morphology of the film is very sensitive to the drop time of the anti-solvent.When the dropout time is too early,the film is needle-like growth,and more holes.With the delay of the dropping time,the surface of the film gradually changed from loose and pinhole state to high density,and the effect of chlorobenzene was the best at high speed of18 s.When the drop time is too late,the film is restored to needle-like,porous characteristics.Through the XRD pattern and absorption spectrum can also be found,when the drop time is 18 s the crystalline properties of the prepared film and the effect of visible light absorptionare the highest.（2）In the process of forming perovskite film,it was investigated that the relative content of PbI₂ affected perovskite layer and cell devices.When the content of PbI₂ was small or large,although the grain size of the film increases,theintergranular boundaries are separated from each other,resulting in a large number of micro-gap,the device performance is poor.When the concentration of PbI₂ and CH₃NH₃ I is equimolar,the PL intensity is lower than that of CH₃NH₃ I.However,the formation of the film is dense and smooth,and the performance of the prepared device is the best,and the conversion efficiency is 9.5%.（3）The effect of Fe’s doping on the properties of CH₃NH₃PbI3 thin films was studied by two-step solution method.FeCl₂ was studied,through the XRD pattern analysis,the（110）crystal face has a slight movement.When the proportion of FeCl₂ is high,absorption spectrum and PL spectrum analysis shows that the photoluminescence spectra and photoluminescence spectra of the formed perovskite have shifted blue.