Mid-infrared type-II InAs/InAsSb quantum wells integrated on silicon.

Direct integration of III–V semiconductor light sources on silicon is an essential step toward the development of portable, on-chip infrared sensor systems. Driven by the presence of characteristic molecular fingerprints in the mid-infrared (MIR) spectral region, such systems may have a wide range of applications in infrared imaging, gas sensing, and medical diagnostics. This paper reports on the integration of an InAs virtual substrate and high crystalline quality InAs/InAsSb multi-quantum wells on Si using a three-stage InAs/GaSb/Si buffer layer. It is shown that the InAs/GaSb interface demonstrates a strong dislocation filtering effect. A series of strained AlSb/InAs dislocation filter superlattices was also used, resulting in a low surface dislocation density of approximately 4 × 107 cm−2. The InAs/InAsSb wells exhibited a strong photoluminescence signal at elevated temperatures. Analysis of these results indicates that radiative recombination is the dominant recombination mechanism, making this structure promising for fabricating MIR Si-based sensor systems. [ABSTRACT FROM AUTHOR]