ULTRADISPO
Ministerio de Ciencia e Innovación (2021-2024)
Nanodispositivos ultrarrápidos y eficientes para comunicaciones y espectroscopía de THz basados en semiconductores de gap ancho y estrecho
This is an ambitious project aiming to the progress of a broad range of high-frequency semiconductor devices, which will be modelled, characterized and fabricated. The objectives of the research will be to improve the energy efficiency of the devices and to enlarge their functionalities by reaching the THz frequency range. The mid-term goal is to transfer the developments made on the different technologies targeted in this project to systems with practical applications in the fields of ultra-fast communications (for both transmitters and receptors) and sensors for THz spectroscopy. Both classical architectures, such as Schottky barrier diodes, Gunn diodes and HEMT transistors, and novel structures, such as selfswitching diodes (SSDs) and gated-SSDs (G-SSDs), will be addressed, with the common feature that all of them are based on III-V semiconductors, specifically InGaAs as narrow-bandgap semiconductor (oriented to low-power, ultrahigh-frequency applications, above 300 GHz) and GaN as wide bandgap one (oriented to high-power applications below 300 GHz). Two approaches for THz emitters will be studied. Gunn diodes (on both InGaAs and GaN) and frequency-multiplied sources based on Schottky barrier diodes. In the latter case, high-power GaN diodes will be used, so that one of the main issues will be the study of selfheating effects and the optimization of the breakdown voltage. Gated Gunn diodes with the G-SSDs architecture will straightforwardly allow for the modulation of the emitted signal (with simple on-off keying), so that their application to high-speed communications can be envisaged. Moreover, they would allow for wideband tunability; thus, THz spectroscopy is other important field of potential application of the outcomes of the project. The THz detection/receptor side will be tackled by means of the classic Schottky barrier diode technology (with the novelty of the high-power capability of GaN) and with the more innovative TERAFET concept (field effect transistors, FETs, employed as THz detectors), using HEMTs and G-SSDs.
