Emergent Photonics Lab (EPic), Dept. of Physics and Astronomy, University of Sussex, Brighton, BN1 9QH, UK.
Sci Rep. 2017 Aug 29;7(1):9805. doi: 10.1038/s41598-017-08734-z.
We introduce a method for diagnosing the electric surface potential of a semiconductor based on THz surface generation. In our scheme, that we name Optical Pump Rectification Emission, a THz field is generated directly on the surface via surface optical rectification of an ultrashort pulse after which the DC surface potential is screened with a second optical pump pulse. As the THz generation directly relates to the surface potential arising from the surface states, we can then observe the temporal dynamics of the static surface field induced by the screening effect of the photo-carriers. Such an approach is potentially insensitive to bulk carrier dynamics and does not require special illumination geometries.
我们介绍了一种基于太赫兹表面产生的半导体表面电势诊断方法。在我们的方案中，我们称之为光泵整流发射，通过超短脉冲的表面光整流在表面上直接产生太赫兹场，然后用第二光泵脉冲屏蔽直流表面电势。由于太赫兹的产生直接与表面状态引起的表面电势有关，因此我们可以观察到由光载流子屏蔽效应引起的静态表面场的时间动态。这种方法对体载流子动力学不敏感，也不需要特殊的照明几何形状。
