Preparation And Performance Study Of Low-cost Perovskite Solar Cells

With rising energy crisis and environmental problems,seeking non-pollution,clean energy has become our current important topics,among them,the solar cell has been recognized as one of the solutions.Perovskite solar cells were proposed for the first time in 2009.After just a short period of rapid development,its photo-electric conversion efficiency has raised to above 20%,close to the efficiency of crystalline silicon solar cells.Except for the high efficiency,the preparation process of perovskite solar cells is relatively simple,the assemble cost is low,the negative effect on the environment is little.As a result,it has attracted a wide attention from researchers all over the world.But high efficient devices often need the use of expensive organic polymer hole-transporting materials,as well as vacuum evaporation to deposit noble metal electrodes,which definitely cause high cost and huge energy consumption.To this end,we try to find new cheap alternatives for hole-transporting materials to replace traditional organic hole transport materials,and use more common accessible raw materials as electrode materials at the same time.In addition,we also systematically analyze the influence on the charge transfer between the layer interfaces by the blocking layer.Specific work content is as follows:?1?Adopting a simple screen printing method,layered perovskite structure solar cells are assembled on the clean FTO transparent conductive substrate.Titanium dioxide,zirconium dioxide,nickel oxide,carbon electrode are printed in turn,followed by annealing treatment to burn off excess solvent.Then from above carbon electrode perovskite precursor solution is dropped.After that,mild heat is introduced to remove organic solvent.According to the characterizations,the efficiency of the resultant perovskite solar cell can reach 7.5%,with a short circuit current density of13.8 mA cm^-2.Without nickel oxide layer?other conditions are identical?photoelectric conversion efficiency decreases to 6.9%,with the J_SC=12.4 mA cm^-2.Removing nickel oxide layer causes lower efficiency and current density.Through the analysis of IPCE and electrochemical impedance spectroscopy,nickel oxide is found to have certain hole conduction ability.To some extent,it can promote the separation of charge carriers.This work provides a new insight into for the exploration of new cheap hole-transporting materials.?2?We systematically study the zirconium dioxide blocking layer and analyze its role in cell device.Three kinds of solar cells were assembled on FTO glass:titanium dioxide,zirconium dioxide,carbon electrode;titanium dioxide,ytterbium oxide and carbon electrode;titanium dioxide,carbon electrode.Characterizations indicate that the structure of titanium dioxide,zirconium dioxide,and carbon electrode has the best performance,with the photoelectric conversion efficiency of 6.9%and photocurrent density of 16.01 mA cm^-2.The device with ytterbium oxide as a blocking layer has a short circuit current density of 12.22 mA cm^-2 and photoelectric conversion efficiency of 5.6%.This is because the zirconium dioxide has a larger specific surface area than ytterbium oxide,and perovskite crystal can infiltrate into the intergranular pore better,leading to greater photocurrent density and better photoelectric conversion efficiency.Without printing the blocking layer,the photoelectric performance is the worst of only about 3.7%.According to the electrochemical impedance spectroscopy analysis of the device,on the interface between carbon electrode and perovskite,obstacle is less to prevent the recombination of electrons and holes.Namely,electron-hole couple has the highest probability to recombine,thus the photocurrent is very low.In order to reduce the comprehensive cost of the battery,we don't use the expensive hole-transporting materials and avoid evaporation of precious metal electrodes.Good photoelectric conversion performance was still obtained by using low-cost raw materials.This has good significance for the development of perovskite solar cells especially on lowering the cost and industrial production.