超快时间分辨光电子显微镜技术及应用

Ultrafast time-resolved photoemission electron microscopy and its applications

光电子显微镜是一种基于光电效应的电子显微镜,利用样品不同空间位置光电子产量的差异作为图像衬度进行投影成像。其成像速度快、空间分辨率高、探测无损伤等特点和优势,在表面科学、表面等离激元学、半导体学等学科有着广泛应用。另外,结合超快光泵浦探测技术为光电子显微镜提供了高时间分辨能力,特别适用于高时空分辨的动力学过程研究。时间分辨光电子显微镜是具备多维度直观测量的技术方法,为研究人员开辟了新的道路。文章首先简要回顾电子显微成像技术的发展,然后介绍在表面等离激元学和半导体物理领域中应用光电子显微镜的最新进展,最后介绍北京大学最近建设的超快光电子显微镜系统和相关研究工作及展望。

Photoemission electron microscopy （PEEM） is a type of electron microscopy based on the photoelectric effect, in which the difference of photoemission yield in space is used as the image contrast. Owing to its outstanding features such as high speed imaging, ultra-high spatial resolution and nondestructive measurement, extensive applications of PEEM have been reported in surface physics, surface plasmonics and semiconductor science. In addition, ultrafast pump and probe techniques provide sufficient time resolution for kinetic studies with high spatiotemporal resolution. PEEM with multidimensional and intuitive measuring methods has opened up new venues for researchers. In this paper we first review the development of microscopic imaging and current progress in the application of PEEM to surface plasmonics and semiconductor science. We then describe the femtosecond-time resolved PEEM system and relevant research in Peking University, followed by a discussion of future prospects.