Demonstration of a 320×256 two-color focal plane array using InAs/InGaAs quantum dots in well detectors

We report the demonstration of a two-color infrared focal plane array based on a voltage-tunable quantum dots-in-well (DWELL) design. The active region consists of multiple layers of InAs quantum dots in an In0.15Ga0.85As quantum well. Spectral response measurements yielded a peak at 5.5μm for lower biases and at 8–10μm for higher biases. Using calibrated blackbody measurements, the midwavelength and long wavelength specific detectivity (D*) were estimated to be 7.1×1010cmHz1∕2∕W(Vb=1.0V) and 2.6×1010cmHz1∕2∕W(Vb=2.6V) at 78 K, respectively. This material was processed into a 320×256 array and integrated with an Indigo 9705 readout chip and thermal imaging was achieved at 80 K.