Semiconductor Nanodevices for Room temperature THz Emission and Detection (ROOTHz)

Research Project, 2010 – 2013

ROOTHz project addresses the bottleneck of Terahertz Science and Technology, where the fabrica-tion of room temperature, continuous wave, compact, tunable and powerful sources (at low cost, if possible) is the prime challenge.<br/>THz radiation (also called T-rays), whose frequency range lies between microwaves and infrared light in the electromagnetic spectrum, opens the possibility for a new imaging and spectroscopic technology with a broad range of applications, from medical diagnostic (without the damage pro-duced by ionizing radiation such as X-rays), industrial quality control or security-screening tools. T rays sources must be obtained at the limits of electronics from one side and optical systems from the other, resulting in a lack of efficient and practical radiation sources. In ROOTHz we propose to exploit THz Gunn oscillations in novel (narrow and wide bandgap) semiconductor nanodevices, which have been predicted by simulations but not experimentally confirmed yet.<br/>We aim at the fabrication not only of solid state emitters but also detectors at THz frequencies by exploiting the properties of both wide and narrow bandgap semiconductors and the advantages pro-vided by the use of novel device architectures such as slot-diodes and rectifying nano diodes (nano-channels with broken symmetry so called self-switching diodes, SSDs). The simplicity of the tech-nological process used for the fabrication of these diodes is remarkable, since it only involves the etching of insulating trenches or recess lines on a semiconductor surface (a single step of high reso-lution lithography). Furthermore, their particular geometry allows providing Gunn oscillations overcoming the classical frequency limit (around 300GHz). The fabrication of THz detectors with the same technology will complement this objective and allow the demonstration of a simple THz detection/emission subsystem at the conclusion of the project.