The Application Of PbS Quantum Dots In Perovskite Solar Cells

Just a few short years of development,the photoelectric conversion efficiency of perovskite solar cells have far more than the traditional dye-sensitised solar cells and quantum dot solar cells,even can be equivalent to that of silicon-based solar cells,this indicates it has huge development potential and supposed to replace the silicon-based solar cells on the market now,enter the commercial.With perovskite solar solar cells business into a target,we also need to get a higher photoelectric conversion efficiency,at this stage,most researchers are studying how to improve the quality of the perovskite membrane,as well as the carrier transmission rate of electron and hole transport layer,then to obtain the higher photoelectric conversion efficiency of solar cells.But for the commercialization of the perovskite solar cells,there are two other problems need to solve,the first,reduce the making cost of perovskite solar cells;the second,the stability of the perovskite solar cells.In this paper,we starting from the actual situation,using commercial carbon slurry as the electrode to replace expensive Au and the all preparation process is in the air,that is more convenient than ever before in the glove box.For improve the photoelectric conversion efficiency of the solar cells,this paper will be introduced to the PbS light absorption layer,that will be sensitized with perovskite and increases the range of light absorption,thus effectively increasing the current density of the solar cells,improve the efficiency.The main research content is as follows:(1)Through the coating method to the commercial carbon slurry preparation of electrodes,fabricate the structure of FTO/TiO2/CH3NH3PbI3/C in the air without Hole-transporting materials.The perovskite film were characterized by XRD,SEM,at the same time,we also characterized the solar cells' section by SEM.The results showed that the surface coverage is good,little holes,good crystallization,the carbon layer has a better contact with the perovskite film,Finally,we obtained 7.78%photoelectric conversion efficiency of the solar cells.(2)First,adopt the method of thermal injection to prepared PbS,and then scatter the PbS to CH3NH3I isopropyl alcohol solution,when using two steps to prepared perovskite,the PbI2 film soaked in the solution.Bying the photocurrent density-voltage,dark current,impedance,XRD,SEM,monochromatic incident photon-to-electron conversion efficiency,ultraviolet visible light absorption to research the influence of PbS for the quality of the film,the absorption capacity,carrier transmission properties.The results found that PbS have a better effect on the crystallization of perovskite,coverage,and particle size,it will increase the rang of its light absorption.At the same time,when the concentration of the PbS quantum dot is added to 36 ?g/mL,the short circuit current density of the battery can reach 23.2 mA/cm2,and the highest photoelectric conversion efficiency of the solar cells is 11.4%.