In(Ga)As Quantum Ring Terahertz Photodetector With Cutoff Wavelength at 175 $\mu$ m

An InAs-GaAs quantum ring infrared photodetector has been fabricated successfully. The photodetector demonstrates a cutoff wavelength at 175 mum (1.7 THz) and the detectivity of 1.3times10
⁷
cm Hz
^1/2
/W at 80 K. The precise control of the In(Ga)As ring height by capping GaAs layer thickness is responsible for extension of the detector response to terahertz range.