Reduced-dimensional (quasi-2D) perovskite materials are widely applied for perovskite photovoltaics due to their remarkable environmental stability. However, their device performance still lags far behind traditional three dimensional perovskites, particularly high open circuit voltage (V_oc) loss. Here, inhomogeneous energy landscape is pointed out to be the sole reason, which introduces extra energy loss, creates band tail states and inhibits minority carrier transport. We thus propose to form homogeneous energy landscape to overcome the problem. A synergistic approach is conceived, by taking advantage of material structure and crystallization kinetic engineering. Accordingly, with the help of density functional theory guided material design, (aminomethyl) piperidinium quasi-2D perovskites are selected. The lowest energy distribution and homogeneous energy landscape are achieved through carefully regulating their crystallization kinetics. We conclude that homogeneous energy landscape significantly reduces the Shockley-Read-Hall recombination and suppresses the quasi-Fermi level splitting, which is crucial to achieve high V_oc.

降维（准二维）钙钛矿材料由于其卓越的环境稳定性而被广泛应用于钙钛矿光伏发电。然而，它们的器件性能仍然远远落后于传统的三维钙钛矿，特别是开路电压（ V _oc ）损耗较高。在这里，不均匀的能量景观被指出是唯一的原因，它引入了额外的能量损失，产生带尾态并抑制少数载流子传输。因此，我们建议形成同质能源格局来克服这个问题。通过利用材料结构和结晶动力学工程，构思了一种协同方法。因此，在密度泛函理论指导的材料设计的帮助下，选择了(氨甲基)哌啶鎓准二维钙钛矿。通过仔细调节其结晶动力学，可以实现最低的能量分布和均匀的能量景观。我们得出的结论是，均匀的能量景观显着减少了肖克利-里德-霍尔复合并抑制了准费米能级分裂，这对于实现高V _oc至关重要。