Mingels S, Porshyn V, Bornmann B, Lützenkirchen-Hecht D, Müller G
FB C Physics Department, University of Wuppertal, 42119 Wuppertal, Germany.
Rev Sci Instrum. 2015 Apr;86(4):043307. doi: 10.1063/1.4919011.
We have completed an ultra-high vacuum system for sensitive fast electron spectroscopy from cold cathodes in triode configuration under high electric fields E (<100 MV/m) and pulsed tunable laser illumination (3.5 ns, 10 Hz, hν = 0.5-5.9 eV, and 0.3-17 mJ). The cathodes are prepared and inserted under clean room conditions and can be precisely 3D-positioned, cooled or heated (77-400 K). Commissioning results with the upgraded system are presented. Field emission measurements with a W tip yielded an energy resolution of 14 meV at 4 eV pass energy and a precise determination of the emitter work function, size, and temperature. Photoemission spectroscopy of short electron bunches from a virgin and laser-ablated S-GaP crystal and quantum efficiency measurements revealed surface states, energy relaxation, and band structure effects. In conclusion, this novel system is ready now for the development and characterization of photo-induced field emission cathodes.
我们已经完成了一个超高真空系统，用于在高电场E（<100 MV/m）和脉冲可调谐激光照射（3.5 ns，10 Hz，hν = 0.5 - 5.9 eV，以及0.3 - 17 mJ）下，对三极管配置中的冷阴极进行灵敏的快速电子能谱分析。阴极在洁净室条件下制备并插入，可进行精确的三维定位、冷却或加热（77 - 400 K）。文中给出了升级系统的调试结果。用钨针尖进行的场发射测量在4 eV通过能量下得到了14 meV的能量分辨率，并精确测定了发射极的功函数、尺寸和温度。对原始的和激光烧蚀的S - GaP晶体产生的短电子束进行的光电子能谱分析以及量子效率测量揭示了表面态、能量弛豫和能带结构效应。总之，这个新颖的系统现在已准备好用于光致场发射阴极的开发和表征。
