Carrier mobility is one of the crucial parameters determining the electronic device performance. We apply the light-induced transient grating technique to measure independently the carrier diffusion coefficient and lifetime, and to reveal the impact of additives on carrier transport properties in wet-cast CH₃NH₃PbI₃ (MAPbI₃) perovskite films. We use the high excitation regime, where diffusion length of carriers is controlled purely by carrier diffusion and not by the lifetime. We demonstrate a four-fold increase in diffusion coefficient due to the reduction of localization center density by additives; however, the density dependence analysis shows the dominance of localization-limited diffusion regime. The presented approach allows us to estimate the limits of technological improvement—carrier diffusion coefficient in wet-cast layers can be expected to be enhanced by up to one order of magnitude.

中文翻译：

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具有添加剂的高激发MAPbI ₃钙钛矿层中的扩散增强

载流子迁移率是决定电子设备性能的关键参数之一。我们应用光诱导瞬态光栅技术来独立地测量载流子扩散系数和寿命，并揭示添加剂对载流子传输特性在湿铸CH冲击₃ NH ₃碘化铅₃（MAPbI ₃）钙钛矿片。我们使用高激发机制，其中载流子的扩散长度完全由载流子扩散而不是寿命来控制。由于添加剂降低了定位中心密度，我们证明了扩散系数增加了四倍。然而，密度依赖性分析显示了局限性扩散机制的主导地位。提出的方法使我们能够估计技术改进的极限，可以预期湿铸层中的载流子扩散系数将提高一个数量级。