采用叠合式石墨烯电极的新型Cs0.05(FA0.85MA0.15)0.95Pb(I0.85Br0.15)3 钙钛矿太阳能电池研究

Recently, perovskite solar cells (PSCs) have gained more and more concern for its high power conversion efficiency (PCE) and low manufacturing cost. However, the stability of PSCs is still far from satisfactory and hinders its commercialization. In this work, we fabricate carbon-based perovskite solar cells (C-PSCs) with mixed-cation lead mixed-halide perovskite absorber (Cs0.05(FA0.85MA0.15)0.95Pb(I0.85Br0.15)3) and stacking graphene electrode to achieve high efficiency and excellent stability. The efficiency of C-PSCs reaches 16.2%. The stacking graphene electrodes are formed by low-cost and facile spray approaches. Stability of C-PSCs in humid environment is improved benefiting from the hydrophobic nature of carbon materials. Meanwhile, perovskite containing Cs+ monovalent inorganic cation also contributes to the photochemical stability. Electrochemical impedance spectroscopy (EIS) and J-V curve are measured and precise models are built to analyze the photogeneration and carrier transport properties of C-PSCs and Au electrode PSCs (Au-PSCs). J-V plot fitting shows lower ideal factor and dark saturate current density for C-PSCs, which indicates fine interfacial contact and less nonradiative recombination centers. However, due to the sparse contact of two detached semi-cells connected by graphene, the series resistance of C-PSCs extracted from the EIS model is higher than Au-PSCs. Moreover, the \'parallel-plate capacitor\' like stacking electrode architecture impacts a lot in low frequency region of EIS curves.