Energy carrier evolution is crucial for material performance. Ultrafast microscopy has been widely applied to visualize the spatiotemporal evolution of energy carriers. However, direct imaging of small amounts of energy carriers on nanoscale remains difficult due to extremely weak transient signals. Here we present a method for ultrasensitive and high-throughput imaging of energy carrier evolution in space and time. This method combines femtosecond pump-probe techniques with interferometric scattering microscopy (iSCAT), named Femto-iSCAT. The interferometric principle and unique spatially-modulated contrast enhancement increase the transient image contrast by >2 orders of magnitude and enable the exploration of new science. We address three important and challenging problems: transport of different energy carriers at various interfaces, heterogeneous hot electron distribution and relaxation in single plasmonic resonators, and distinct structure-dependent edge state dynamics of carriers and excitons in optoelectronic semiconductors. Femto-iSCAT holds great potential as a universal tool for ultrasensitive imaging of energy carrier evolution in space and time.

中文翻译：

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通过能量载体演化的宽场飞秒干涉成像解密材料性能

能量载体演化对材料性能至关重要。超快显微镜已被广泛应用于可视化能量载体的时空演变。然而，由于瞬态信号极弱，在纳米尺度上对少量能量载体进行直接成像仍然很困难。在这里，我们提出了一种在空间和时间上对能量载体演化进行超灵敏和高通量成像的方法。该方法将飞秒泵浦探针技术与干涉散射显微镜 (iSCAT) 相结合，称为 Femto-iSCAT。干涉原理和独特的空间调制对比度增强将瞬态图像对比度提高了 2 个数量级以上，并有助于探索新科学。我们解决了三个重要且具有挑战性的问题：不同能量载体在不同界面的运输，单个等离子体谐振器中的异质热电子分布和弛豫，以及光电子半导体中载流子和激子的不同结构依赖的边缘态动力学。Femto-iSCAT 作为一种通用工具具有巨大的潜力，可用于对空间和时间中的能量载体演化进行超灵敏成像。