Near-3 Megapixel Mid-Wave Infrared HgTe Colloidal Quantum Dot Focal Plane Array with 5 μm Pixel Pitch

Currently, mid-wave infrared (MWIR) focal plane arrays (FPAs) are advancing toward lower cost, higher operating temperatures, miniaturization, and enhanced resolution. These developments present challenges for MWIR FPAs based on traditional epitaxial infrared materials such as HgCdTe and InAsSb, which are constrained by complex technological processes. HgTe colloidal quantum dots (CQDs), as zero-dimensional semiconductors, have significantly enhanced the design freedom of FPAs and the operating temperature of devices due to their unique quantum confinement effect, phonon bottleneck effect, and the advantages of solution processing. This provides the potential for the manufacture of MWIR FPAs with larger arrays and smaller pixels (approaching the optical diffraction limit). Here, we have fabricated a high-temperature exciton extraction-enhanced barrier-type MWIR HgTe CQD FPA with an advanced 5 μm pixel pitch and 1920×1536 array specification. The cutoff wavelength is about 4 μm and the blackbody peak detectivity (D*) at zero bias and 150 K is 1 × 109 Jones. The dark current density is between 10–7 and 10–6 A/cm2 within the operating temperature range of 120–200 K. We have also demonstrated MWIR thermal imaging results at 120 K for varying temperature objects at different operating temperatures.