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/sub 0.25/Ga/sub 0.75/As structure is proposed. Devices have an asymmetrically-shaped geometrical form in the plane of the structure and are fabricated as mesas of 2 /spl mu/m 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 device operation from 10 GHz up to 2.52 THz at room temperature is demonstrated.