Articles you may be interested inGaAs-based room-temperature continuous-wave 1.59 μ m GaInNAsSb single-quantum-well laser diode grown by molecular-beam epitaxy Appl. Phys. Lett. 87, 231121 (2005); 10.1063/1.2140614Room-temperature, ground-state lasing for red-emitting vertically aligned InAlAs/AlGaAs quantum dots grown on a GaAs(100) substrate Appl.Room-temperature lasing at the wavelength of 1.31 m is achieved from the ground state of an InGaAs/GaAs quantum-dot ensemble. At 79 K, a very low threshold current density of 11.5 A/cm 2 is obtained at a wavelength of 1.23 m. The room-temperature lasing at 1.31 m is obtained with a threshold current density of 270 A/cm 2 using high-reflectivity facet coatings. The temperature-dependent threshold with and without high-reflectivity end mirrors is studied, and ground-state lasing is obtained up to the highest temperature investigated of 324 K.

Growth of room-temperature "arsenic free" infrared photovoltaic detectors on GaSb substrate using metamorphic InAlSb digital alloy buffer layers

Arrays of III–V direct-bandgap semiconductor nanopillars represent promising photovoltaic candidates due to their inherent high optical absorption coefficients and minimized reflection arising from light trapping, efficient charge collection in the radial direction and the ability to synthesize them on low-cost platforms. However, the increased surface area results in surface states that hamper the power conversion efficiency. Here, we report the first demonstration of GaAs nanopillar-array photovoltaics employing epitaxial passivation with air mass 1.5 global power conversion efficiencies of 6.63%. High-bandgap epitaxial InGaP shells are grown in situ and cap the radial p–n junctions to alleviate surface-state effects. Under light, the photovoltaic devices exhibit open-circuit voltages of 0.44 V, short-circuit current densities of 24.3 mA cm−2 and fill factors of 62% with high external quantum efficiencies >70% across the spectral regime of interest. A novel titanium/indium tin oxide annealed alloy is exploited as transparent ohmic anode.

Data are presented characterizing a new process for fabrication of vertical-cavity surface-emitting lasers based on the selective conversion of high Al composition epitaxial AlGaAs to a stable native oxide using ‘‘wet oxidation.’’ The native oxide is used to form a ring contact to the laser active region. The resulting laser active regions have dimensions of 8, 4, and 2 μm. The lowest threshold laser is achieved with the 8-μm active region, with a minimum threshold current of 225-μA continuous wave at room temperature.

Photovoltaic devices using GaAs nanopillar radial p-n junctions are demonstrated by means of catalyst-free selective-area metal-organic chemical vapor deposition. Dense, large-area, lithographically defined vertical arrays of nanowires with uniform spacing and dimensions allow for power conversion efficiencies for this material system of 2.54% (AM 1.5 G) and high rectification ratio of 213 (at ±1 V). The absence of metal catalyst contamination results in leakage currents of ∼236 nA at -1 V. High-resolution scanning photocurrent microscopy measurements reveal the independent functioning of each nanowire in the array with an individual peak photocurrent of ∼1 nA at 544 nm. External quantum efficiency shows that the photocarrier extraction highly depends on the degenerately doped transparent contact oxide. Two different top electrode schemes are adopted and characterized in terms of Hall, sheet resistance, and optical transmittance measurements.

The nanopillar photonic-crystal cavities are arranged in arrays with varying pitch and diameter in order to fine tune the resonant wavelength and Q factor. Each array contains 4 rows and 6 columns of devices. In each row, the radius is varied between 0.15·a and 0.2·a (where a is the inter-pillar pitch). In each column, the inter-pillar pitch is varied between 324 nm and 342 nm. This variation in pitch corresponds to resonant wavelengths between 950 nm and 1000 nm according to the normalized frequency calculated from FDTD simulations (λ = a/ω n , where ω n = 0.342). Fig. S2 shows a dark-field optical microscope image at 50× magnification of an array in PDMS with the inset showing a single device at 150× magnification. Additional rows for other experiments (labeled A) are visible but not reported on in this paper.

Chip-scale integrated light sources are a crucial component in a broad range of photonics applications. III-V semiconductor nanowire emitters have gained attention as a fascinating approach due to their superior material properties 1,2 , extremely compact size 3 , and the capability to grow directly on lattice-mismatched silicon substrates 4,5 . Although there have been remarkable advances in nanowire-based emitters 6-8 , their practical applications are still in the early stages due to the difficulties in integrating nanowire emitters with photonic integrated circuits (PICs). Here, we demonstrate for the first time optically pumped III-V nanowire array lasers monolithically integrated on silicon-on-insulator (SOI) platform. Selective-area growth of purely single-crystalline InGaAs/InGaP core/shell nanowires on an SOI substrate enables the nanowire array to form a photonic crystal nanobeam cavity with superior optical and structural properties, resulting in the laser to operate at room temperature. We also show that the nanowire array lasers are effectively coupled with SOI waveguides by employing nanoepitaxy on a pre-patterned SOI platform. These results represent a new platform for ultra-compact and energy-efficient optical links, and unambiguously point the way toward practical and functional nanowire lasers.Integrating III-V semiconductors on a silicon platform has been widely studied to achieve highperformance and energy-efficient lasers since the demonstration of hybrid III-V/Si lasers. Flip-chip

The manuscript reports that the initial strain relaxation of highly mismatched GaSb layers grown on GaAs (001) is governed by the two-dimensional (2D), periodic interfacial misfit (IMF) dislocation array growth mode. Under optimized growth conditions, only pure 90° dislocations are generated along both [110] and [11¯0] directions that are located at GaSb/GaAs interface, which leads to very low threading dislocation density propagated along the growth direction. The long-range uniformity and subsequent strain relaxation of the 2D and periodic IMF array are demonstrated via transmission electron microscopy and scanning transmission electron microscopy images at GaSb/GaAs interface.