Passivation of interfacial defects of ZnO and CsPbBr₃ by inserting NaSCN in all-inorganic perovskite solar cells

Here, we passivated the interfacial defects of ZnO/CsPbBr₃ by inserting a NaSCN layer between the ZnO electron transport layer and the CsPbBr₃ layer to improve the photoelectric conversion efficiency of ZnO/CsPbBr₃/Carbon structure solar cell. The addition of the NaSCN optimized the morphology of the ZnO surfaces to decrease effectively the roughness. Furthermore, The passivated ZnO electron transport layer improved the deposition quality of CsPbBr₃ films, which reduced the defects at the interface between the ZnO electron transport layer and CsPbBr₃ layer, suppressing non-radiative recombination to enhance device photovoltaic performance. Synergistic passivation of SCN⁻ and Na⁺ ions plays an important role in obtaining high-quality CsPbBr₃ films for boosting the power conversion efficiency (PCE) of the device. Moreover, the passivated solar cells had longer stability than the pristine ones after being placed for 1000 h in the air and at room temperature.