Simulation and optimization of arsenic-implanted THz emitters
  We have used a three-dimensional pseudo-classical Monte Carlo simulation to investigate the effects of As+ ionimplantation on pulsed terahertz radiation emitters. Devices based on surface-field emitters and photoconductive switches have been modelled. Two implantations of As+ ions at 1.0 MeV and 2.4 MeV were found to produce a uniform distribution of vacancies over the volume of GaAs contributing to THz generation in these devices. We calculate that ionimplantation increases the THz bandwidth of the devices with the cost of decreasing the spectral intensity at lower THz frequencies. 
M.B. Johnston, J. Lloyd-Hughes, E. Castro-Camus, M.D. Fraser and C.   Jagadish