The critical role of composition-dependent intragrain planar defects in the performance of MA1-xFAxPbI3 perovskite solar cells
The critical role of composition-dependent intragrain planar defects in the performance of MA1-xFAxPbI3 perovskite solar cells
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成分依赖性晶粒内平面缺陷对MA(1)(-)(x)FA(x)PbI(3)钙钛矿太阳能电池性能的关键作用
DOI：
10.1038/s41560-021-00830-9
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发表时间：
2021-06-14
期刊：
影响因子：
56.7
通讯作者：
Etheridge, Joanne
中科院分区：
文献类型：
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作者：
Li, Wei;Rothmann, Mathias Uller;Etheridge, Joanne
晶内平面缺陷在卤化物钙钛矿太阳能电池器件中的作用仍然难以捉摸。现在，Li等人调整钙钛矿层的成分以最小化平面缺陷密度并观察到器件性能的改善。钙钛矿太阳能电池显示出优异的功率转换效率，长载流子扩散长度和低复合率。这鼓励了一种观点，即晶粒内缺陷是电子良性的，对器件性能的影响很小。在这项研究中，我们改变了MA（1）（-）（x）FA（x）PbI（3）（x = 0-1）中的甲基铵（MA）/甲脒鎓（FA）组成，并比较了晶粒内平面缺陷的结构和密度与器件性能，否则保持器件名义上相同。我们发现，电荷载流子寿命，开路电压赤字和电流密度-电压滞后经验相关的{111}（c）平面缺陷（x = 0.5-1）和{112}（t）孪晶界（x = 0-0.1）的密度和结构。当基本上没有晶内平面缺陷是明显的（x = 0.2）时，发现最佳的性能参数。类似地，通过MASCN蒸气处理FAPbI（3）（x近似于1）降低{111}（c）平面缺陷的密度也改善了性能。这些观察结果表明，除了诸如晶界和界面等公认的参数之外，晶粒内缺陷控制可以为改善钙钛矿太阳能电池性能提供重要途径。
The role of intragrain planar defects in halide perovskite solar cell devices remains elusive. Now, Li et al. tune the composition of the perovskite layer to minimize the planar defect density and observe an improvement in the device performance.Perovskite solar cells show excellent power conversion efficiencies, long carrier diffusion lengths and low recombination rates. This encourages a view that intragrain defects are electronically benign with little impact on device performance. In this study we varied the methylammonium (MA)/formamidinium (FA) composition in MA(1)(-)(x)FA(x)PbI(3) (x = 0-1), and compared the structure and density of the intragrain planar defects with device performance, otherwise keeping the device nominally the same. We found that charge carrier lifetime, open-circuit voltage deficit and current density-voltage hysteresis correlate empirically with the density and structure of {111}(c) planar defects (x = 0.5-1) and {112}(t) twin boundaries (x = 0-0.1). The best performance parameters were found when essentially no intragrain planar defects were evident (x = 0.2). Similarly, reducing the density of {111}(c) planar defects through MASCN vapour treatment of FAPbI(3) (x approximate to 1) also improved performance. These observations suggest that intragrain defect control can provide an important route for improving perovskite solar cell performance, in addition to well-established parameters such as grain boundaries and interfaces.