Research On The Interface Modification And Structural Design Of Perovskite Solar Cell

Perovskite solar cell has attracted wide interests because of its simple fabrication process and excellent photoelectric performance.The typically investigated planar perovskite solar cell possesses sandwich architecture consisting of an electron transport layer,perovskite absorber and hole transport layer(HTL),however,large numbers of interfaces exist in this device structure which shall induce bad interfacial defect recombination and consequently inefficient carrier separation and low device stability,further inhibiting its practical application.Optimizing the structure of perovskite solar cell is an effective way to improve the cell's performance and its stability.In this paper,with regard to the issue of the trap recombination between the perovskite/HTL interface and the degradation of HTL,we conducted researches on the interface modification and structural design of planar perovskite solar cell.The main subjects are as follows:(1)A thin F4 TCNQ layer was introduced between perovskite/HTL by spin-coating the F4 TCNQ solution in chlorobenzene to modify the perovskite interface.Results show that this F4 TCNQ material is a good electron acceptor,which can form a dipole interaction with the perovskite interface,so the perovskite interface can be p-type doped,thus intensifying the electric field at the perovskite / HTL interface and promoting the charges separation and transmission.In addition,the F4 TCNQ layer also plays an important role in the perovskite surface defects passivation,which can effectively reduce the recombination rate at the surface and subsurface of perovskite,thus contributing to the improvement of the photoelectric properties of the device.(2)The removal of HTL in standard perovskite solar cell was investigated and optimization of HTL-free perovskite solar cell was conducted.We established a model of HTL-free perovskite by using one-dimensional simulation software wxAMPS,and analyzed the effect of semiconductor material characteristic on the device efficiency through adjusting of each layer and materials' property,including the absorber doping,thickness and the energy band alignment at the perovskite / back contact electrode.In the end,we obtained the optimized HTL-free perovskite cell with efficiency of up to 17%.