A compact, electrically driven light source integrated on silicon is a key component for large-scale integration of electronic and photonic integrated circuits. Here we demonstrate electrically ...injected continuous-wave lasing in InP-based microdisk lasers coupled to a sub-micron silicon wire waveguide, fabricated through heterogeneous integration of InP on silicon-on-insulator (SOI). The InP-based microdisk has a diameter of 7.5 mum and a thickness of 1 mum. A tunnel junction was incorporated to efficiently contact the p-side of the pn-junction. The laser emits at 1.6 mum, with a threshold current as low as 0.5 mA under continuous-wave operation at room temperature, and a threshold voltage of 1.65 V. The SOI-coupled laser slope efficiency was estimated to be 30 muW/mA, with a maximum unidirectional output power of 10 muW.
In this work we present a new epitaxial lift-off (ELO) approach based on the use of a strained AlAs/InAlAs superlattice (SL) as sacrificial layer for InP related materials. Such an ELO process ...enables the fabrication and transfer of a thin active III-V heterostructure via its separation from its III-V parent substrate using selective chemical etching. The strategy is of particular interest for large area devices such as solar cells. The process studied here also allows the substrate reuse for a low-cost approach based on III-V-based device fabrication. In order to realize the ELO process on InP substrates, the main difficulty is the lack of lattice-matched materials offering the high chemical etching selectivity needed over both the substrate and the lattice-matched alloys of the active heterostructure. The present study therefore contributes effective strategy for overcoming the latter constraints. The AlAs/InAlAs SL was thus explored as a potential candidate as sacrificial layer for the InP lattice matched materials. The growth conditions of such SLs were investigated to produce low defect SLs compatible with the properties of an optimal sacrificial layer. The under-etching behavior of such SLs in a hydrofluoric acid-based solution was also studied in detail. The results show that advantageous under-etching rates, high enough for a full wafer detachment, combined with a low defect density, can be obtained with novel sacrificial layers based on such thin AlAs/InAlAs SL. Finally, the fabrication of solar cells via an active heterostructure grown over an optimized SL on a monolithic substrate and via a thin reported active heterostructure was performed. The solar cells perform well and demonstrate the suitability of such SLs as a sacrificial layer for InP related materials.
•AlAs/InAlAs superlattices allow growth of thicker sacrificial layers than AlAs layers.•High under-etching rates can be obtained on low defect AlAs/InAlAs superlattices.•State of the art InGaAs solar cell performances obtained over optimized superlattice.•Fabrication of InGaAs solar cells via epitaxial lift-off is demonstrated.
We demonstrate unidirectional bistability in microdisk lasers electrically pumped and heterogeneously integrated on SOI. The lasers operate in continuous wave regime at room temperature and are ...single mode. Integrating a passive distributed Bragg reflector (DBR) on the waveguide to which the microdisk is coupled feeds laser emission back into the laser cavity. This introduces an extra unidirectional gain and results in unidirectional emission of the laser, as demonstrated in simulations as well as in experiment.
Vertical Fabry Perot cavities (VFPC) have been extensively studied, especially for the realization of vertical-cavity surface emitting lasers (VCSELs). They are traditionally composed of two ...Distributed Bragg Reflectors (DBR) which reflectivity has to be sufficient in order to obtain highly resonant cavity, which is particularly necessary for laser emission in VCSELs. As a consequence, DBRs consist generally in very thick layer stacks. In this paper, we demonstrate the smallest conceivable high Q vertical Fabry-Perot cavity, using ultra-thin and highly-efficient photonic crystal slab mirrors instead of conventional DBRs, which enable moreover a control of the polarization.
III-V/Si photonics by die-to-wafer bonding Roelkens, G.; Van Campenhout, J.; Brouckaert, J. ...
Materials today (Kidlington, England),
07/2007, Volume:
10, Issue:
7-8
Journal Article
Peer reviewed
Open access
Photonic integrated circuits offer the potential of realizing low-cost, compact optical functions. Silicon-on-insulator (SOI) is a promising material platform for this photonic integration, as one ...can rely on the massive electronics processing infrastructure to process the optical components. However, the integration of a Si laser is hampered by its indirect bandgap. Here, we present the integration of a direct bandgap III-V epitaxial layer on top of the SOI waveguide layer by means of a die-to-wafer bonding process in order to realize near-infrared laser emission on and coupled to SOI.
We report on the performance of a compact multi- wavelength laser (MWL) source heterogeneously integrated with and coupled to a silicon-on-insulator (SOI) waveguide circuit. The MWL consists of four ...InP-based microdisk lasers, coupled to a common SOI wire waveguide. The microdisk lasers operate in continuous-wave regime at room temperature, with a threshold current around 0.9 mA and a waveguide-coupled slope efficiency of up to 8 muW/mA, for a microdisk diameter of 7.5 mum. The output spectrum contains four laser peaks uniformly distributed within the free-spectral range of a single microdisk. While thermal crosstalk is negligible, laser peak output powers vary up to 8 dB for equal microdisk drive currents, as a result of loss due to coupling with higher order modes supported by the 1-mum-thick microdisks. This nonuniformity could be eliminated by reducing the microdisk thickness.
Epitaxial SrTiO3 (STO) layers were grown on GaAs(001) substrates by molecular beam epitaxy. A Ti-based surface passivation was used prior to STO growth. The different steps of this passivation ...procedure are discussed on the basis of reflection high energy electron diffraction experiments. We also show that the STO/GaAs template presents an excellent structural quality with a flat surface, an abrupt semiconductor/oxide interface, and a good crystallinity. Such STO/GaAs templates open perspectives for the integration of perovskite oxides on semiconductor substrates.
•Epitaxial growth of SrTiO3 on GaAs(001)•Oxide molecular beam epitaxy•Ti-based surface passivation
We have studied the growth of a SrTiO3 shell on self-catalyzed GaAs nanowires grown by vapor–liquid–solid assisted molecular beam epitaxy on Si(111) substrates. To control the growth of the SrTiO3 ...shell, the GaAs nanowires were protected using an arsenic capping/decapping procedure in order to prevent uncontrolled oxidation and/or contamination of the nanowire facets. Reflection high energy electron diffraction, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy were performed to determine the structural, chemical, and morphological properties of the heterostructured nanowires. Using adapted oxide growth conditions, it is shown that most of the perovskite structure SrTiO3 shell appears to be oriented with respect to the GaAs lattice. These results are promising for achieving one-dimensional epitaxial semiconductor core/functional oxide shell nanostructures.
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