InSb Quantum Dots for Mid-infrared Laser Applications
We are studying self-assembled InSb quantum dot nanostructures for use in mid-infrared diode lasers. Because of the type II band line-up, InSb/InAs quantum dots (QDs) are capable of light emission at wavelengths beyond 3 µm. Together with collaborators at the Ioffe Institute, we have realized a dense array of self-assembled InSb QDs having a mean lateral diameter of ~2.5 nm and a sheet density of ~1012 cm-2. These sub-monolayer InSb nanostructures exhibit bright photo-luminescence and low temperature lasing in the MIR spectral range.
Fig.1 Band line-up and photoluminescence of sub-monolayer InSb QD in InAS matrix
We have also fabricated InSb quantum dot LEDs and observed electro-luminescence near 4 μm at room temperature and coherent emission at low temperature.
Fig. 2 Mid-infrared electroluminescence from an InSb QD LED at room temperature, and coherent emission from sub-monolayer InSb QD in a diode laser.