| Abstrakt: |
Normal-incidence InAs/GaAs quantum-dot detectors have been grown, fabricated, and characterized for mid-infrared detection in the temperature range from 78 to 150 K. Due to the presence of an Al[sub 0.3]Ga[sub 0.7]As current blocking layer in the heterostructure, the dark current is very low, and at T=100 K, I[sub dark]=1.7 pA for V[sub bias]=0.1 V. The peak of the spectral response curve is at λ∼4 μm, with Δλ/λ=0.3 and V[sub bias]=0.1 V. At T=100 K, for V[sub bias]=0.3 V, the peak detectivity, D[sup *], is 3×10[sup 9] cm Hz[sup 1/2]/W, and the peak responsivity, R[sub p], is 2 mA/W with a photoconductive gain of g=18. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR] |
