DataSheet2_Investigation of the S-Shaped Current–Voltage Curve in High Open-Circuit Voltage Ruddlesden–Popper Perovskite Solar Cells.zip

We report our investigation on the S-shaped current–voltage characteristics in a hot-casting–processed (BA)₂ (MA)₃Pb₄I₁₃ Ruddlesden–Popper (RP) perovskite solar cell. The two-dimensional perovskite solar cells are fabricated with NiO_x as the hole transport layer (HTL), which leads to significantly high open-circuit voltage (V_oc). The champion device shows a V_oc of 1.21 V and a short current density (J_sc) of 17.14 mA/cm², leading to an overall power conversion efficiency (PCE) of 13.7%. Although the PCE is much higher than the control device fabricated on PEDOT:PSS, a significant S-shaped current–voltage behavior is observed in these NiO_x-based devices. It is found that the S-shaped current–voltage behavior is related to the lower dimensional phase distribution and crystallinity at the bottom interface of the RP perovskite layer, and the S-shaped distortion is less severe after the device ageing test.