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A GaSb quantum-well (QW) laser diode grown monolithically on a 5° miscut Si (001) substrate is presented. The III-Sb epi-structure is grown monolithically on the miscut Si substrate via a thin (50 nm) AlSb nucleation layer. The 13% lattice mismatch between AlSb and Si is accommodated by a self-assembled, 2D array of interfacial misfit dislocations (IMF). The 5° miscut geometry enables simultaneous IMF formation and anti-phase domain suppression. The 1 mm × 100 µm GaSb QW laser diode operates under pulsed conditions at 77 K with a threshold current density of 2 kA/cm2 and a maximum peak power of ∼20 mW. Furthermore, the device is characterised by a 9.1 Ω forward resistance and a leakage current density of 0.7 A/cm2 at -5 V. [ABSTRACT FROM AUTHOR]

The electro-optic properties of 1.3 µm self-assembled InAs/GaAs quantum dots grown by metal organic chemical vapour deposition are reported. The linear and quadratic electro-optic coefficients are 2.4×10-11 m/V and 3.2×10-18 m2/V2, respectively, which are significantly larger than those of GaAs bulk materials. Also, the linear electro-optic coefficient is almost comparable to that of lithium niobate. [ABSTRACT FROM AUTHOR]

Reported is super-luminescent emission under room-temperature, continuous-wave conditions from GaSb quantum-well-based light emitting diodes (LED), monolithically integrated on Si (100) substrates. The LEDs are realised with substrate growth temperature under 500°C for the entire process and the Si (001) substrate is non-miscut. The lattice mismatch at the AlSb/Si interface is accommodated by interfacial misfit dislocation arrays (IMF) resulting in low defect-density III-Sb material without thick metamorphic buffers. The devices are grown in etched trenches on the Si substrate to reduce anti-phase domains in the III-Sb. The n-Si substrate is contacted directly and thus current flows through the III-Sb/Si IMF interface. The diodes have extremely low leakage current density (Jleakage<0.2 A/cm2) in the reverse bias (-10 V) and show very good diode characteristics but exhibit a slightly elevated forward resistance (R∼ 27 Ω), likely to be because of the IMF. The super-luminal spectra peaks at 2.14 µm with maximum output power ∼0.125 mW. [ABSTRACT FROM AUTHOR]

Monolithic vertical cavity surface emitting lasers (VCSELs) on Si are demonstrated. The GaSb multi-quantum well active region embedded in an Al(Ga)Sb half-wave cavity spacer layer enables lasing under room-temperature optically-pumped conditions. The 13% lattice mismatch is accommodated by a spontaneously formed 2-D array of 90° misfit dislocations at the AlSb/Si interface. This growth mode produces very low defect density (∼8×105/cm2) and relaxed materials growth (98%) without the use of a buffer layer. Presented are VCSEL lasing spectra, light-in against light-out curves along with defect density measurements performed by microscopy and etch-pit density. A threshold excitation density of Ith=0.1 mJ/cm2 and a multimode lasing spectrum peaked at 1.62 µm, results from a 3 mm pump-spot size. [ABSTRACT FROM AUTHOR]

The use of multiple layers of self-organised InAs quantum dots as a very effective dislocation filter is demonstrated. In0.5Ga0.5As/GaAs quantum dot lasers grown directly on silicon substrates with the InAs quantum dot buffer layer exhibit substantially reduced threshold currents (Jth∼900 A/cm2), compared to devices grown on silicon without the dot buffer layer (Jth≥1500 A/cm2). [ABSTRACT FROM AUTHOR]