Plasmonic enhanced quantum well infrared photodetector with high detectivity

We report a normal-incident quantum well infrared photodetector (QWIP) strongly coupled with surface plasmon modes. A periodic hole array perforated in gold film was integrated with In(0.53)Ga(0.47)As/InP QWIP to convert normal-incident electromagnetic waves into surface plasmon waves, and to excite the intersubband transition of carriers in the quantum wells. The peak responsivity of the photodetector at similar to 8 mu m was similar to 7 A/W at the bias of 0.7 V at 78 K with the peak detectivity as high as similar to 7.4 x 10(10) cm Hz(1/2)/W. The full width at half maximum of the response spectrum was only similar to 0.84 mu m due to a narrow plasmonic resonance. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3419885]