Effect of InGaAs surface states and interfaces on the photo-generated THz pulse shape

We present some 3D modeling of the physical behavior of a 1.55 mum photoconductive switch (PCS). The first one compares PCS with Ohmic contact versus devices with Schottky contact. The results are very close. The second study stress on the incidence of the Fermi-level pinning at the surface of the InGaAs layer on the amplitude of the THz pulse. Also, we present the results of an interdigited photoconductive switch (IPS) modeling.