Detection of terahertz/sub-terahertz radiation by asymmetrically-shaped 2DEG layers

A diode structure to detect THz/subTHz radiation based on an MBE-grown modulation-doped GaAs/Al(0.25)Ga(0.75)As structure is proposed. Devices have an asymmetrically-shaped geometrical from in the plane of the structure and are fabricated as mesas of 2 µm depth by wet etching. The incident terahertz/sub-terahertz radiation induces a voltage signal over the ends of the sample. Detection by non-uniform carrier heating effects under external illumination is explained and the devices operation from 10 GHz up to 2.52 THz at room temperature is demonstrated