Study of carbon-based hole-conductor-free perovskite solar cells

In this paper, the perovskite solar cells (PSCs) with the structure of FTO glass/compact TiO2/mesoporous TiO2/CH3NH3PbI3/carbon electrode were designed and fabricated. The CH3NH3PbI3 absorption layers were prepared using one-step solvent-engineering method. The effects of volume ratios of dimethyl sulfoxide (DMSO) to N, N-dimethylformamide (DMF) and molar ratios of PbI2 to CH3NH3I (MAI) on structure and morphology of CH3NH3PbI3 absorption layers, as well as photovoltaic performance of PSCs were studied. The results show that the PSCs based on a specific ratio of PbI2:MAI = 1:1.4 and DMSO:DMF = 1:3 exhibited an optimal photovoltaic performance, yielding an open-circuit voltage (Voc) of 0.72 V, short-circuit current density (Jsc) of 25.98 mA/cm2, fill factor (FF) of 0.46, and power conversion efficiency (PCE) of 8.45%. And the incident photon-to-electron conversion efficiency (IPCE) is close to 85% between 400 and 600 nm visible region.