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.