“…The simulated devices feature d = 100 nm and E C = 0, 0.3 eV, 0.5 eV (these values are consistent with the conduction band step at a Al x Ga 1−x As/GaAs heterojunction in a staircase APD [14], [24], where E C 0.355 eV for x = 0.45 [25], [26]. Moreover, we have always applied an electric field along the x direction, E x = 400, 500 and 600 kV/cm, to ensure that all the carriers exit from the simulation domain.…”