silicon and indium-phosphide

Topics: Biomimetic Materials; Biomimetics; Bionics; Crystallization; Equipment Design; Indium; Neural Networks, Computer; Phosphines; Semiconductors; Silicon; Synapses

We report a high lasing wavelength uniformity of optically pumped InP-based microdisk lasers processed with electron-beam lithography, heterogeneously integrated with adhesive bonding on silicon-on-insulator (SOI) waveguide circuits and evanescently coupled to an underlying waveguide. We study the continuous wave laser emission coupling out of the SOI via a grating coupler etched at one side of the waveguide, and demonstrate a standard deviation in lasing wavelength of nominally identical devices on the same chip lower than 500 pm. The deviation in the diameter of the microdisks as low as a few nanometers makes all-optical signal processing applications requiring cascadability possible.

Topics: Electric Conductivity; Equipment Design; Equipment Failure Analysis; Indium; Lasers; Phosphines; Refractometry; Silicon; Surface Plasmon Resonance; Systems Integration

We report on a hybrid InP/Si photonic crystal nanobeam laser emitting at 1578 nm with a low threshold power of ~14.7 μW. Laser gain is provided from a single InAsP quantum well embedded in a 155 nm InP layer bonded on a standard silicon-on-insulator wafer. This miniaturized nanolaser, with an extremely small modal volume of 0.375(λ/n)(3), is a promising and efficient light source for silicon photonics.

Topics: Computer-Aided Design; Equipment Design; Equipment Failure Analysis; Indium; Lasers; Miniaturization; Nanoparticles; Nanotechnology; Particle Size; Phosphines; Quantum Dots; Silicon

We fabricated a novel lateral-current-injection-type distributed feedback (DFB) laser with amorphous-Si (a-Si) surface grating as a step to realize membrane lasers. This laser consists of a thin GaInAsP core layer grown on a semi-insulating InP substrate and a 30-nm-thick a-Si surface layer for DFB grating. Under a room-temperature continuous-wave condition, a low threshold current of 7.0 mA and high efficiency of 43% from the front facet were obtained for a 2.0-μm stripe width and 300-μm cavity length. A small-signal modulation bandwidth of 4.8 GHz was obtained at a bias current of 30 mA.

Topics: Arsenicals; Equipment Design; Equipment Failure Analysis; Feedback; Gallium; Indium; Lasers; Membranes, Artificial; Phosphines; Refractometry; Silicon

Vertical indium phosphide nanowires have been grown epitaxially on silicon (111) by metalorganic vapor-phase epitaxy. Liquid indium droplets were formed in situ and used to catalyze deposition. For growth at 350 degrees C, about 70% of the wires were vertical, while the remaining ones were distributed in the 3 other <111> directions. The vertical fraction, growth rate, and tapering of the wires increased with temperature and V/III ratio. At 370 degrees C and V/III equal to 200, 100% of the wires were vertical with a density of approximately 1.0 x 10(9) cm(-2) and average dimensions of 3.9 mum in length, 45 nm in base width, and 15 nm in tip width. X-ray diffraction and transmission electron microscopy revealed that the wires were single-crystal zinc blende, although they contained a high density of rotational twins perpendicular to the <111> growth direction. The room temperature photoluminescence spectrum exhibited one peak centered at 912 +/- 10 nm with a FWHM of approximately 60 nm.

Topics: Catalysis; Indium; Microscopy, Electron, Transmission; Nanowires; Phosphines; Silicon; X-Ray Diffraction

A new method is presented for measurements of friction of microsized particles on surfaces. Specifically in this work, the particles are alumina with diameters between approximately 1 and 50 microm and the surfaces are InP, Si, and Cr. Friction is analyzed, its components are determined, and the friction coefficients are estimated from the experimental results. The technique and the specific instrument allow measurements of coefficients of friction for spherical particles with radii as small as 1 microm. For smaller sizes, the instrument needs to be modified by using a more powerful power supply, actuator with extended frequency and amplitude ranges, cooling of the actuator and the power supply, and the related mechanical modifications of the sample holder.

Topics: Aluminum Oxide; Chromium; Electric Power Supplies; Friction; Indium; Linear Models; Miniaturization; Motion; Particle Size; Phosphines; Silicon; Vibration

The relationship between crystal quality and the properties of indium phosphide nanowires grown on silicon (111) has been studied by transmission electron microscopy, photoluminescence spectroscopy, and photoelectrochemistry. Wires with no defects and with {111} twin boundaries parallel and perpendicular to the growth direction were obtained by metalorganic vapor-phase epitaxy using liquid indium catalyst. Room temperature photoluminescence from the defect-free nanowires is approximately 7 times more intense than that from the wires with twin boundaries. An open-circuit photovoltage of 100 mV is observed for photoelectrochemical cells made with the defect-free nanowires, whereas no photovoltage is recorded for those with twins.

Topics: Electrochemistry; Indium; Luminescence; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; Nanowires; Phosphines; Silicon

Low-temperature time-resolved photoluminescence spectroscopy is used to probe the dynamics of photoexcited carriers in single InP nanowires. At early times after pulsed excitation, the photoluminescence line shape displays a characteristic broadening, consistent with emission from a degenerate, high-density electron-hole plasma. As the electron-hole plasma cools and the carrier density decreases, the emission rapidly converges toward a relatively narrow band consistent with free exciton emission from the InP nanowire. The free excitons in these single InP nanowires exhibit recombination lifetimes closely approaching that measured in a high-quality epilayer, suggesting that in these InP nanowires, electrons and holes are relatively insensitive to surface states. This results in higher quantum efficiencies than other single-nanowire systems as well as significant state-filling and band gap renormalization, which is observed at high electron-hole carrier densities.

Topics: Electrons; Indium; Light; Metal Nanoparticles; Microscopy, Electron, Transmission; Nanotechnology; Phosphines; Semiconductors; Silicon; Time Factors

Patterning of semiconductor surfaces is an area of intense interest, not only for technological applications, such as molecular electronics, sensing, cellular recognition, and others, but also for fundamental understanding of surface reactivity, general control over surface properties, and development of new surface reactivity. In this communication, we describe the use of self-assembling block copolymers to direct semiconductor surface chemistry in a spatially defined manner, on the nanoscale. The proof-of-principle class of reactions evaluated here is galvanic displacement, in which a metal ion, M+, is reduced to M0 by the semiconductor, including Si, Ge, InP, and GaAs. The block copolymer chosen has a polypyridine block which binds to the metal ions and brings them into close proximity with the surface, at which point they undergo reaction; the pattern of resulting surface chemistry, therefore, mirrors the nanoscale structure of the parent block copolymer. This chemistry has the added advantage of forming metal nanostructures that result in an alloy or intermetallic at the interface, leading to strongly bound metal nanoparticles that may have interesting electronic properties. This approach has been shown to be very general, functioning on a variety of semiconductor substrates for both silver and gold deposition, and is being extended to organic and inorganic reactions on a variety of conducting, semiconducting, and insulating substrates.

Topics: Arsenicals; Gallium; Germanium; Indium; Molecular Structure; Nanostructures; Phosphines; Polymers; Semiconductors; Silicon; Surface Properties

Topics: Arsenicals; Gallium; Gold; Indium; Ions; Metal Nanoparticles; Metals; Microscopy, Atomic Force; Microscopy, Electron, Scanning; Nanostructures; Nanotechnology; Nitrogen; Phosphines; Semiconductors; Silicon; Surface Properties; Surface-Active Agents