Study of the optimal photoresponse, speed, and temperature performance of terahertz photoelectric tunable-step detectors

A GaAs/AlGaAs-based photoelectric tunable-step (PETS) terahertz (THz) detector with a symmetric dipole antenna is demonstrated in this work as a model system to carry out a systematic study of the in-plane photoelectric effect. We derive the optimal values for the antenna gap, depth of the 2DEG, and other geometrical parameters from numerical simulations, and fabricate a detector with optimized dimensions. It shows a high responsivity (˜2.5 kV/W) to 1.9-THz radiation with a short response time (˜2 μs). The temperature dependence of the photoresponse of the PETS detector shows a capability of operating up to 75 K. The results of this work deepen the understanding of the in-plane photoelectric effect and provide a universal reference for the design of future high responsivity, fast PETS THz detectors operating at high temperatures.