Study On The Device Structure And Performance Of ZnO Nanorod Arrays Based Perovskite Solar Cell

As an emerging new type of solar cell,organic inorganic hybrid perovskite solar cell employ MA(FA)PbX3(X=I,Br,Cl)crystal as light absorbing layer.Owing to its numerous outstanding photoelectric properties such as high light absorption coefficient,high carrier mobility,long carrier diffusion length,smaller carrier effective mass,better crystallization,dominant shallow point defects.This kind of material has great research potential in the solar field.Since perovskite crystal's first application in a solar cell structure in 2009,the photoelectric conversion efficiency has reached to 22.1%in less than 10 years.However,in order to commercialize the PSC.Improving its efficiency,lowering the product cost as well as enhancing the stability are the 3 most important and difficult issues that need to be done.Therefore,replacement of expensive materials,simplification of experimental methods,performance improvement of the electron transport materials,perovskite crystal and the modification of the interface condition between them are some of the research hotspots.We chose 1D ZnO nanorod arrays as ETL for the PSC device for its cheap and easy to prepare.Focusing on the optimization of the photoelectric performance of the 1D ZnO nanorod arrays,perovskite crystal,the interface condition between them.PSC stability has also been studied as well.This article carried out 3 aspects as follows.Firstly,a simplified ZnO compact layer/ZnO nanorod array/MAPbI3/HTL/Au structure was studied.Smooth and flat perovskite film was achieved by altering the morphology of the perovskite crystal.Then the ETL structure was optimized.During the growth of ZnO nanorod arrays,the surface morphology of short ZnO nanorod was found to be of great help in enhancing the interfacial performance with perovskite crystal.The theoretical structure for PSC based ZnO nanorod arrays was raised by the analysis of the growth mechanism of ZnO.Secondly,a relatively simple surface treatment method was introduced owing to the chemical properties of ZnO and the previous assumption was realized successfully.Large numbers of ZnO nanoparticles was found to be formed on the surface of the longer ZnO nanorods.Test results showed that the carrier recombination rate was greatly suppressed.The surface appearance of the perovskite crystal based on the acid treated ZnO nanorod was also strengthened,which mainly appear in the decrease of pinhole defects on the surface of the light absorbing layer.Based on the fact that Cl doped MAPbI3 has longer charge diffusion length,the absorption capacity of perovskite crystal was enhanced through Cl doping.Jsc has got an increment of 11%than the undoped device.Efficiency of the optimized PSC was 13.3%.Finally,Pb doped ZnO compact layer was studied based on all the previous optimized methods.The crystallization and electrical properties of ZnO compact layer were improved after Pb doping.The spin coating made Pd doped ZnO compact layer was smoother than the undoped sample,vertical orientation of ZnO nanorod arrays was also significantly enhanced.EIS test showed that the series resistance of Pb doped samples was greatly reduced.Indicating that the addition of Pb has effectively enhanced the conductivity of ZnO compact layer,which enhance FF as a result.PSC based on 1%Pb doped ZnO nanorod sample exhibited the best cell performance and photoelectric conversion efficiency reached to 14.5%.In order to obtain better device stability,FA and FAMA hybrid perovskite crystal were briefly learned.SEM,UV and other tests guarantee that FAPb(I,Cl)3 has better crystallization performance together with ideal bandgap.The stability of the FA device was much better than the former ones.however,due to some unknown faults in the experimental section,the cell performance was not improved.This article focus on the latest research hot spot:PSC.Systematically study was carried out for ZnO nanorod arrays based PSC.ETL,light absorbing layer and the interface contact between them were studied in detail.The research results have some positive meaning for future PSC study and application of ZnO nanostructure in other fields.