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 degrees C grown 2.2 ML quantum dot (QD) with QD annealing time similar to 30 s. The QRs show the broad PL spectrum which is blue shifted from QD about 100meV. 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 pm which has a spectral detectivity of 2.3 x 10(11) cm Hz(1/2)/W at 10 K under 1.2 V bias.