Triple-Barrier Resonant Tunneling Diodes for Sensitive THz Detection

The demand for sensitive, compact, and room-temperature-operable terahertz (THz) detectors, suitable for mobile and battery-powered applications, has become increasingly important with the growing use of THz technology in fields such as imaging, sensing, and communications. This thesis investigates the Triple-Barrier Resonant Tunneling Diode (TBRTD) semiconductor device as a zero-bias THz detector, leveraging its unique transport properties, non-linear current-voltage characteristics, and low-noise zero-bias operation to achieve high sensitivity in direct THz detection. The research focuses on the theoretical modeling, experimental characterization, and integration of the TBRTD to verify and optimize its performance in the THz frequency range. A large-signal equivalent circuit model is developed to predict TBRTD behavior and is validated through on-wafer scattering parameter measurements up to 500 GHz. On-wafer experimental measurements of detector performance demonstrate a peak responsivity of 2123 V/W and a Noise Equivalent Power (NEP) as low as 1.15 pW/√Hz in the WR2 band (330–500 GHz). Successful integration with a planar on-chip logarithmic spiral antenna, designed for broadband THz operation up to 1 THz, demonstrates effective performance in the 220–330 GHz range, underscoring the potential of the TBRTD for real-world THz applications. These findings establish the TBRTD as a high-performance solution for efficient THz direct detection, paving the way for advancements in high-resolution imaging, non-invasive diagnostics, and high-speed wireless communications.