In(Ga)As Quantum Rings for Terahertz Detectors

The In(Ga)As quantum ring infrared photodetector (QRIP) were investigated. The quantum ring (QR) is transformed from 500 °C grown 2.2 ML quantum dot (QD) with QD annealing time ∼30 s. The QRs show the broad PL spectrum which is blue shifted from QD about 100 meV. The resultant QRIP is a broadband terahertz detector. The response extends from 3 to 100 THz with peak responsivity of 127 mA/W at 23 µm which has a spectral detectivity of 2.3 ×10 11 cm Hz 1/2 /W at 10 K under 1.2 V bias.