All-inorganic, hole-transporting-layer-free, carbon-based CsPbIBr2 planar solar cells with ZnO as electron-transporting materials

Abstract In this paper, all-inorganic, hole-transporting-layer-free (HTLF), carbon-based CsPbIBr2 planar solar cells with zinc oxide (ZnO) as electron-transporting materials (ETMs) were studied for the first time. The reported all-inorganic, HTLF, carbon-based cesium lead iodide dibromide (CsPbIBr2) solar cells used titanium dioxide (TiO2) as ETMs, which usually required a high sintering temperature of 500 °C. Here, ZnO ETMs were annealed at 120 °C. The highest power conversion efficiency (PCE) of 7.60%, with a short-circuit current (Jsc) of 11.60 mA/cm2, an open-circuit voltage (Voc) of 1.03 V and the fill factor (FF) of 0.63, was obtained. Furthermore, the thermal and humid stabilities of the solar cells were studied. The perovskite solar cells were placed at 10% humidity and room temperature for 624 h and the PCE of perovskite solar cells only decreased by 10%. While the perovskite solar cells were placed at 80 °C and 0% humidity for 192 h, the PCE of the solar cells decreased by 4%.