NORMAL-INCIDENCE INTERSUBBAND (IN, GA)AS GAAS QUANTUM-DOT INFRARED PHOTODETECTORS/

We report the device performance of normal-incidence (In, Ga)As/GaAs q uantum dot intersubband infrared photodetectors. A primary intersubban d transition peak is observed at the wavelength of 13 mu m (E-0 --> E- 1) and a secondary peak at 11 mu m (E-0 --> E-2). The measured energy spacing in the conduction band of the quantum dots is in good agreemen t with low temperature photoluminescence measurement and calculations. A peak detectivity of 1 x 10(10) cm Hz(1/2)/W at 13 mu m was achieved at 40 K for these devices. (C) 1998 American Institute of Physics. [S 0003-6951(98)01440-5].