The electrical potential distribution within photovoltaic devices plays critical roles in governing charge carrier dynamics and the device performance. Here we present the electrical potential distribution within highly efficient perovskite solar cells (PSCs) in working status. We found the major potential drop existing at the perovskite/mesoporous TiO₂ interface, indicating one diode junction in mesoporous PSCs. In contrast, the major potential drop was found on both sides of the perovskite layer in planar PSCs, exhibiting two diode junctions where the charge carriers could be recombined more easily than single-junction PSCs. We further controlled the position of diode junctions in planar PSCs by changing the dopant concentration. The undesirable charge recombination was largely suppressed, which enabled a better ideality factor and a higher efficiency 20.12% for planar PSCs with the increase of donor concentration. The present study will be helpful for understanding the fundamental mechanism within PSCs and achieving high device efficiency.

光伏器件内的电势分布在控制电荷载流子动力学和器件性能方面起着至关重要的作用。在这里，我们介绍处于工作状态的高效钙钛矿太阳能电池（PSC）内的电势分布。我们发现钙钛矿/中孔TiO ₂存在主要的潜在下降界面，指示中孔PSC中的一个二极管结。相反，在平面PSC中钙钛矿层的两侧都发现了主要的电位降，表现出两个二极管结，其中的电荷载流子比单结PSC更容易重组。我们通过更改掺杂剂浓度进一步控制了平面PSC中二极管结的位置。随着供体浓度的增加，平面PSC的不良电荷重组得到了极大的抑制，从而实现了更好的理想因子和更高的效率20.12％。本研究将有助于理解PSC中的基本机制并实现高设备效率。