Ⅰ前言外逸电子(Exoelectron)系指从经受某种处理后的材料(金属、半导体、介质)表面发射的低能电子。最早发现并提出这一效应的是德国物理学家J.Kramer,故又称为克拉玛效应。当材料经受辐照、变形、磨蚀、氧化、相变、吸附等处理后,从材料表面在激发或无激发的情况下就开始发射电子。这些电子能量普遍较低,一般只有零点几到几个电子伏。为提高探测灵敏度往往应 I. INTRODUCTION Exoelectrons are low-energy electrons emitted from the surface of a material (metal, semiconductor, dielectric) subjected to a certain treatment. Earliest to find and put forward this effect is the German physicist J.Kramer, it is also known as the Karama effect. When the material is subjected to irradiation, deformation, abrasion, oxidation, phase change, adsorption and other treatments, electrons are emitted from the surface of the material with or without excitation. These electron energies are generally low, usually only a few to a few electron volts. To improve the detection sensitivity often should