Simulating nanoisland layers in THz detectors using a Monte Carlo method

Abstract

We present a Monte Carlo model that simulates the effects of non-equilibrium carrier-carrier scattering and the presence of layers of ErAs nanoislands in a GaAs terahertz antenna detector. To minimize computing time, we split the model into two simulations on numerical grids with optimized resolutions. First, we calculate the effects of the ErAs nanoislands on carrier lifetime in a high resolution volume of GaAs. We then incorporate those results into a larger, lower resolution, two-dimensional simulation that models the antenna detector. The computational results match experimental data presented by Kadow et al. [Appl. Phys. Lett. 75, 3548-3550 (1999)] and show that the lifetime of the carriers is closely linked to the periodicity of the nanoisland layers. Our results also highlight how the periodicity of the nanoisland layers affects the sensitivity and bandwidth of the terahertz detector, information that can be used to create custom devices with optimal parameters.