The Study On The Application Of Transition Metal Carbides In Carbon Based Perovskite Solar Cells

In recent years,organic-metal halide perovskite solar cells?PSCs?based on carbon counter electrode?CCE?have attracted extensive attention from researchers.A typical carbon-based PSC consists of four parts:FTO conductive glass,electron transport layer,perovskite layer and CCE.Among them,perovskite serves dual purposes of photosensitizer and hole transport,and its film-forming quality determines the performance of the device.Therefore,the study on high-quality perovskite film becomes the top priority.Literature shows that the quality of perovskite film can be significantly improved by doping additives in the perovskite layer of PSCs.However,there is no study on the application of transition metal carbides as additives in the perovskite layer.In this paper,five kinds of transition metal carbides were added into the perovskite layer to study the effect of different transition metal carbides on the performance of the cell.Specific contents of the study are as follows:?1?Three Group VI transition metals,i.e.molybdenum carbide?Mo₂C?,tungsten carbide?WC?and chromium carbide?Cr₃C₂?were prepared and doped into the perovskite layer?P?respectively and assembled into carbon-based perovskite solar cells?C-PSCs?.The effects of Mo₂C/P,WC/P and Cr₃C₂/P with different doping concentrations on the performance of the device were studied.The results show that the performance of the device can be improved by doping an appropriate amount of Mo₂C or WC.The photon-to-electron conversion efficiency?PCE?reaches 6.85%on WC/P-based C-PSCs at the doping concentration of 1.0 mg/mL,an increase of 29%compared with the undoped device.The corresponding short-circuit current density,open-circuit voltage and fill factor are 22.77 mA/cm2,0.61 V and 0.49 respectively.?2?Titanium carbide?TiC?and niobium carbide?NbC?were prepared.These two carbides were used as additives in the perovskite layer respectively and assembled into C-PSCs with FTO conductive glass,electron transport layer and CCE.The J-V test,electrochemical and spectral characterization were carried out to study the influence of the concentration of the additives on the performance of C-PSCs.The results show that the effects of the two carbides on the efficiency of the device differ greatly.TiC doping can improve the performance of the device,while NbC doping reduces the efficiency of the device.When the doping concentration of TiC is 0.5 mg/mL,the PCE of the device increases by 6.02%and its open circuit voltage is 0.73 V.