Mixed cation and anion based perovskites solar cells exhibited enhanced stability under outdoor conditions, however, it yielded limited power conversion efficiency when TiO₂ and Spiro-OMeTAD were employed as electron and hole transport layer (ETL/HTL) respectively. The inevitable interfacial recombination of charge carriers at ETL/perovskite and perovskite/HTL interface diminished the efficiency in planar (n-i-p) perovskite solar cells. By employing computational approach for uni-dimensional device simulator, the effect of band offset on charge recombination at both interfaces was investigated. We noted that it acquired cliff structure when the conduction band minimum of the ETL was lower than that of the perovskite, and thus maximized interfacial recombination. However, if the conduction band minimum of ETL is higher than perovskite, a spike structure is formed, which improve the performance of solar cell. An optimum value of conduction band offset allows to reach performance of 25.21%, with an open circuit voltage (V_oc) of 1231 mV, a current density J_sc of 24.57 mA/cm² and a fill factor of 83.28%. Additionally, we found that beyond the optimum offset value, large spike structure could decrease the performance. With an optimized energy level of Spiro-OMeTAD and the thickness of mixed-perovskite layer performance of 26.56% can be attained. Our results demonstrate a detailed understanding about the energy level tuning between the charge selective layers and perovskite and how the improvement in PV performance can be achieved by adjusting the energy level offset.

混合的阳离子和阴离子基钙钛矿太阳能电池在室外条件下表现出增强的稳定性，但是，当分别将TiO ₂和Spiro-OMeTAD用作电子和空穴传输层（ETL / HTL）时，它产生的功率转换效率有限。ETL /钙钛矿和钙钛矿/ HTL界面上不可避免的电荷载流子界面重组降低了平面（压区）的效率）钙钛矿太阳能电池。通过对一维器件模拟器采用计算方法，研究了带偏移对两个界面上电荷复合的影响。我们注意到，当ETL的导带最小值低于钙钛矿的导带最小值时，它就获得了悬崖结构，从而使界面重组最大化。但是，如果ETL的导带最小值高于钙钛矿，则会形成尖峰结构，从而提高太阳能电池的性能。导带偏移的最佳值可实现25.21％的性能，开路电压（V _oc）为1231 mV，电流密度J _sc为24.57 mA / cm ²填充率为83.28％。此外，我们发现，超出最佳偏移值，大的尖峰结构可能会降低性能。通过优化的Spiro-OMeTAD能量水平和混合钙钛矿层的厚度，可以达到26.56％的性能。我们的结果证明了对电荷选择层和钙钛矿之间能级调整的详细了解，以及如何通过调整能级偏移来实现PV性能的提高。