Research On The Effective Layer And Interface Of Perovskite Solar Cells

In recent years,organic inorganic perovskite solar cells have become the focus in the field of photovoltaic because of their high energy conversion efficiency and simple solution preparation process.This paper focuses on the energy conversion efficiency,stability?service life?and cost of perovskite solar cells.The three factors are the most important to determine the commercialization of solar cells.We study on the effective layer of perovskite solar cells and device fabrication,optimization method and interface modification on perovskite solar cells,the main contents are as follows:1)The preparation method of the effective layer of perovskite was explored,and the high quality MAPbI₃ perovskite thin film was prepared by solvent engineering solution method.The planar inverted heterojunction perovskite solar cell device was prepared.The energy conversion efficiency?PCE?of the standard MAPbI₃ perovskite solar cells over 10%;By further optimizing the components of the perovskite precursor and using the interface modification method,the energy conversion efficiency?PCE?of the standard MAPbI_3-xCl_x perovskite solar cells is as high as 14.3%2)The perovskite effective layer was annealed by"mixed-solvents annealing".The crystal quality of perovskite films annealed in IPA/DMF mixed solvent?100:1,v/v?atmosphere was obviously improved and the average grain size increases to about 500nm.The PCE of MAPbI₃ perovskite solar cell is over 15%.The PCE of MAPbI_3-xCl_x perovskite solar cells is up to 18.9%,V_oc is 1.03 V,J_sc reaches 22.70 mA/cm²,the FF reaches 0.82,and the stability of the device is improved obviously.3)The use of organic materials PCBM modified perovskite effective layer,lower concentration?<10 mg/ml?PCBM modified perovskite can improve the quality of the perovskite effective layer,passivation of perovskite traps and defects,especially the grain boundary related traps,improve the charge separation in the perovskite,inhibit the trap-assisted recombination,and improve the transport efficiency of the carriers.The energy conversion efficiency?PCE?of the MAPbI_3-xCl_x perovskite solar cells prepared by this method is increased to 18.6%,the efficiency is improved more than 35%,the efficiency distribution of the devices is concentrated,and the repeatability is good.The stability of the device is improved obviously.4)The OSF method is proposed,that is,the perovskite effective layer and the electron transport layer are prepared in one step.Under these conditions,part of the PCBM exists in the grain boundaries of the perovskite effective layer,passivation of perovskite defects,improve crystalline quality,inhibit the recombination;part of the PCBM formed continuous and complete electron transport layer on the surface of perovskite layer,the charge can be more effective transported from perovskite to PCBM electron transport layer,the charge transport efficiency is improved.The PCE of the MAPbI_3-xCl_x perovskite solar cell prepared by this method is increased to 16.9%,the stability of the device has been significantly improved,more importantly,it greatly simplifies the preparation process of the device,whicn has important significance for large-scale application.