| In recent years,organic-inorganic hybrid perovskite materials have attracted a lot of attention for their impressive characters such as wide absorption range,high mobility,long carrier lifetime,tunable band gap and simple preparation method,and become a hot research point in the field of solar cells.The power conversion efficiency has risen from initial 3.8%to 22.1%rapidly just in a few years.However,the hole transport materials such as Spiro-OMeTAD and so on,and metal electrode such as expensive metal material as Au and Ag in the procedure of making PSCs are very expensive and need complex synthesis process,which restrict the development of PSCs.Reducing the cost of device preparation and improving the stability have become the urgent problems in the research field of PSCs.Based on this,this study aims at making high performance carbon based PSCs without HTM.This study adopts low-pressure vapor-assisted deposition process to fabricate MAPbI3 perovskite with larger perovskite grain size and smoother perovskite film,and use it to make HTM-free FTO/c-TiO2/C60/MAPbI3/Carbon planar-heterojunction solar cells,and then do some researches on the study of carbon electrode,including the comparation of preparation methods,optimization of drying temperature,and component regulation.By analysing the morphology,anaylysing the conduction mechanism,and analysing the device photoelectric character of the two methods,it was found that carbon electrode made by screen printing method was in close contact with the perovskite,and the electrode components were continuous without holes.The PSCs based on this method shows high photoelectric performance of 3.47%.On this basis,futher study on the effect of the drying temperature of carbon electrode on perovskite is made.And through the analysis of crystal structure,surface morphology and steady state fluorescence of perovskite of re-heating at different temperatures,it is determined that the carbon electrode drying at 70 ? can effectively prevent decomposition of perovskite and further improve the photoelectric performance of the device.In order to further improve the device efficiency,we consider of adding composition in carbon electrode,and start from two aspects:enhancing the contact between carbon electrode and perovskite,and increasing the conductivity of electrodes,we added MAI and graphene respectively and together.The effects of each component on the device performance were studied by electrochemical impedance spectroscopy and steady state fluorescence analysis.Through the research and analysis,we can see that adding MAI can improve the interface contact between electrode and perovskite,and adding graphene can improve the conductivity of electrodes.The two at the same time can not only improve the interface contact,but also improve the conductivity of the electrode,so that the maximum efficiency of the device is achieved.The optimal device can reach the efficiency of 7.22%and maintain good stability in 45 days.Using simple carbon electrode preparation and cheap commercial carbon paste and adding commonly used additives,this study improves the cell efficiency from initial 1%to 7.22%,which provides a reference for the researches of planer PSCs based on carbon electrode. |
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