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 TiO 2 /mesoporous TiO 2 /CH 3 NH 3 PbI 3 /carbon electrode were designed and fabricated. The CH 3 NH 3 PbI 3 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 PbI 2 to CH 3 NH 3 I (MAI) on structure and morphology of CH 3 NH 3 PbI 3 absorption layers, as well as photovoltaic performance of PSCs were studied. The results show that the PSCs based on a specific ratio of PbI 2 :MAI = 1:1.4 and DMSO:DMF = 1:3 exhibited an optimal photovoltaic performance, yielding an open-circuit voltage (V oc ) of 0.72 V, short-circuit current density (J sc ) of 25.98 mA/cm 2 , 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.