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

Abstract

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.

Next-generation mid-infrared sources

“…The initial demonstrations of InSb QD growth focused more on growth parameters and structural characterization than optical properties, though subsequent efforts showed weak emission close to the InAs bandgap [257]. The addition of Ga to the InSb layers, in an effort to form In(Ga)Sb QDs on InAs, successfully increased emission wavelength to as far as ∼8 μm, though direct microstructural evidence for InGaSb QD formation was not shown [258,259]. Although the demonstrations of In(Ga)Sb QD growth on InAs utilize a variety of epitaxial techniques, all suggest that the formation of these QDs is extremely sensitive to growth parameters, with subsequent growth studies suggesting that the window for InSb QD formation is rather narrow, but that the addition of Ga appears to result in the clear formation of InGaSb QDs with emission wavelengths in the 5-6 μm range, demonstrating strong confinement of holes in the InGaSb QD valence band [248,252].…”

Transmission of Infrared Radiation Through Metallic Photonic Crystal Structures

“…7(a), which helps IR absorption more efficiently in comparison with the IR incident wave just passing through the QDs by a single optical path. The InGaSb QDs is located from 300 nm to 850 nm from the device surface corresponding to different device designs that reported in our former paper [9]. The total thickness of 10 repeats of the D2B is about 850 nm, their locations along the Z-direction as marked in Fig.…”

“…As described above the D2B detectors demonstrated possibility of higher operating temperatures, which is promising for significantly reducing the IR camera's cost [9], [10]. However, its responsivity is still low due to limited QD stack numbers govern by the material lattice mismatch and epitaxy growth time.…”

“…Various solutions and alternatives to realize such goals have been widely explored, for instance, intra-subband transition based type-I quantum dot infrared photodetectors (QDIPs) [2]- [4] and type-II strained layer superlattices (T2SLs) IR detectors [5]- [7]. Recently, type-II In(Ga)Sb quantum dot (QD) IR detectors with high operating temperatures up to 225 K have been reported as a means of detection mechanism based on interband transitions from bound hole states in the QDs to continue states in the surrounding bulk material [8], [9], so-called dot-to-bulk (D2B) detectors, as detailed in our previous publication [9].…”

“…This study is aiming to optimize mPhC structures, and thereby providing an effective integration solution for enhancing performance of our D2B IR detectors. The D2B IR detector has promising potential to operate at high temperatures in the MWIR/LWIR regimes, but its response was limited by numbers of the D2B repeats in the active region of the detectors [9]. We experimentally demonstrated that adjusting the mPhC structure parameters such as the lattice constant can tune the SPR to match the IR detector's operating wavelength.…”