论文标题
探测卤化物钙钛矿太阳能电池中的离子缺陷景观
Probing the ionic defect landscape in halide perovskite solar cells
论文作者
论文摘要
金属卤化物钙钛矿中的点缺陷在确定其性质和光电性能方面起着关键作用。但是，许多公开问题仍未得到解决。在这项工作中，我们采用阻抗光谱和深度瞬态光谱法来表征三碘甲基甲基铅（$ mapbi_3 $）perovskites中的离子缺陷景观，其中缺陷是通过分数改变前体stoichiontry而故意引入的。我们的结果强调了缺陷对电子景观的深远影响，例如它们对设备内置电位的影响，因此是开路电压的。当阳离子和阴离子都被视为移动时，即使是低离子密度也可能会对电子景观产生影响。此外，我们发现所有测量的离子缺陷都满足了迈耶 - 内尔德尔规则，其特征能量与基础离子跳跃过程有关。这些发现支持卤化物钙钛矿化合物中缺陷的一般分类。
Point defects in metal halide perovskites play a critical role in determining their properties and optoelectronic performance; however, many open questions remain unanswered. In this work, we apply impedance spectroscopy and deep-level transient spectroscopy to characterize the ionic defect landscape in methylammonium lead triiodide ($MAPbI_3$) perovskites in which defects were purposely introduced by fractionally changing the precursor stoichiometry. Our results highlight the profound influence of defects on the electronic landscape, exemplified by their impact on the device built-in potential, and consequently, the open-circuit voltage. Even low ion densities can have an impact on the electronic landscape when both cations and anions are considered as mobile. Moreover, we find that all measured ionic defects fulfil the Meyer--Neldel rule with a characteristic energy connected to the underlying ion hopping process. These findings support a general categorization of defects in halide perovskite compounds.
