Photoluminescence and photoresponse from InSb/InAs-based quantum dot structures.

InSb-based quantum dots grown by metal-organic vapor-phase epitaxy (MOVPE) on InAs substrates are studied for use as the active material in interband photon detectors. Long-wavelength infrared (LWIR) photoluminescence is demonstrated with peak emission at 8.5 µm and photoresponse, interpreted to originate from type-II interband transitions in a p-i-n photodiode, was measured up to 6 µm, both at 80 K. The possibilities and benefits of operation in the LWIR range (8-12 µm) are discussed and the results suggest that InSb-based quantum dot structures can be suitable candidates for photon detection in the LWIR regime.