We report a giant bowing of the spin-orbit splitting energy ${\ensuremath{\Delta}}_{0}$ in dilute ${\mathrm{GaAs}}_{1\ensuremath{-}x}{\mathrm{Bi}}_{x}$ alloy for Bi concentrations ranging from 0% to 1.8%. This is first observation large relativistic correction host electronic band structure induced by just few percent isoelectronic doping semiconductor material. It opens up possibility tailoring semiconductors spintronic applications.

Growth of InGaN/GaN light-emitting devices on nonpolar or semipolar planes offers a viable approach to reducing eliminating the issues associated with polarization-related electric fields present in c-plane III-nitride heterostructures. Although progress device performance has been rapid since introduction high-quality free-standing and GaN substrates, full appreciation materials challenges unique semiconductors slower emerge. Only recently have researchers begun understand such as origins...

This article presents a theoretical analysis of dislocation behavior and stress relaxation in semipolar III-nitride heteroepitaxy, e.g., for AlxGa1−xN InyGa1−yN layers grown on {hh2−h−m}- or {h0h−m}-type planes GaN substrates. We demonstrate that the shear stresses unique inclined basal (0001) plane do not vanish such growth geometries. leads to onset processes heterostructures via glide slip systems 〈1−1−20〉(0001) formation misfit dislocations (MDs) with Burgers vectors (a/3)〈1−1−20〉-type...

We report on a III-nitride vertical-cavity surface-emitting laser (VCSEL) with tunnel junction (TJ) intracavity contact. The violet nonpolar VCSEL employing the TJ is compared to an equivalent tin-doped indium oxide (ITO) shows threshold current density (Jth) of ∼3.5 kA/cm2, ITO Jth 8 kA/cm2. differential efficiency also observed be significantly higher than that VCSEL, reaching peak power ∼550 μW, ∼80 μW for VCSEL. Both VCSELs display filamentary lasing in aperture, which we believe...

Abstract In this work, we demonstrate highly doped GaN p–n tunnel junction (TJ) contacts on III–nitride heterostructures where the active region of device and top p-GaN layers were grown by metal organic chemical vapor deposition n-GaN was NH 3 molecular beam epitaxy to form TJ. The regrowth interface in these hybrid devices found have a high concentration oxygen, which likely enhanced tunneling through diode. For optimized regrowth, best had total differential resistivity 1.5 × 10 −4 Ω cm 2...

We report time-resolved terahertz spectroscopy measurements of the electronic transport properties dilute GaAs bismide and nitride alloys. The electron mobility for GaAs1−yBiy (y=0.84%) extracted from Drude fits to transient complex conductivity was ∼2800cm2∕Vs at a carrier density 2.7×1018cm−3, close 3300cm2∕Vs measured similar density. did not decrease significantly Bi concentrations up 1.4%. In contrast, GaNxAs1−x (x=0.84%) GaNxAs1−x−yBiy (x=0.85%, y=1.4%) films exhibited non-Drude...

A model of basal plane stacking faults as boundaries between incoherently scattering domains in m-plane GaN films is reviewed. m-Plane are analyzed with a modified version the Williamson–Hall analysis order to determine length-scale coherent and tilt-mosaic contribution X-ray rocking curve widths for primary in-plane directions. This shows that predominant source rocking-curve width anisotropy films, indicate can be used non-destructive technique measuring fault densities m-GaN films.

Misfit strain relaxation via misfit dislocation (MD) generation was observed in heteroepitaxially grown (Al,In)GaN layers on free-standing semipolar (112¯2) GaN substrates. Cross-section transmission electron microscope images revealed MD arrays at alloy heterointerfaces, with the line direction and Burgers vector parallel to [11¯00] [112¯0], respectively. The structure is consistent plastic by glide (0001) plane. Since only slip plane, associated tilt of epitaxial layers. tilt, measured...

The effects of NH3 flow, group III flux, and substrate growth temperature on indium incorporation surface morphology have been investigated for bulk InGaN films grown by ammonia molecular beam epitaxy. unintentional impurity elements (H, C, O) in was studied as a function polar (0001) GaN sapphire templates, nonpolar (101¯0) GaN, semipolar (112¯2), (202¯1) substrates. Enhanced observed both surfaces relative to c-plane, while reduced (112¯2) co-loaded conditions. Indium increase with...

A molecular beam epitaxy regrowth technique was demonstrated on standard industrial patterned sapphire substrate light-emitting diode (LED) epitaxial wafers emitting at 455 nm to form a GaN tunnel junction. By using an HF pretreatment the before regrowth, voltage of 3.08 V 20 A/cm2 achieved small area devices. high extraction package developed for comparison with flip chip devices which utilize LED floating in silicone over BaSO4 coated header and produced peak external quantum efficiency...

We investigate the electronic properties of GaAs1−xBix by photoluminescence at variable temperature (T=10–430K) and high magnetic field (B=0–30T). In GaAs0.981Bi0.019, localized state contribution to PL is dominant up 150K. At T=180K diamagnetic shift free-exciton states reveals a sizable increase in carrier effective mass with respect GaAs. Such an cannot be accounted for enhanced character valence band states, solely. Instead, it suggests that also Bloch conduction are heavily affected...

$\mathrm{Ga}{\mathrm{As}}_{1\ensuremath{-}x}{\mathrm{Bi}}_{x}$ is a mixed-anion semiconductor alloy. In the As-rich regime $(0.4%<x<4%)$, isovalent Bi creates series of bound states but this alloy nonetheless exhibits properties characteristic regular semiconductors. The dual impurity-alloy character can be tuned by varying temperature. Below $100\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, multiple appear at low energy in luminescence spectrum. These are associated with pseudodonor potential...

Epilayer lattice tilt has been observed by X-ray diffraction for heteroepitaxial AlGaN and InGaN films on (1122) semipolar GaN substrates. Complementary transmission electron microscopy demonstrates that epilayer is a consequence of interfacial misfit dislocations with Burgers vectors a/3[1120] glide the (0001) basal plane [inclined ∼58° to (1122)]. The dislocation lines are parallel [1100], consistent anisotropy in scans orthogonal in-plane directions. had an vector component relieved...

We demonstrate an electrically injected semipolar (112¯2) laser diode (LD) grown on intentionally stress relaxed n-In0.09Ga0.91N waveguiding layer. Detrimental effects of misfit dislocations (MDs) in the proximity active region were effectively suppressed by utilizing a p/n-Al0.2Ga0.8N electron/hole blocking layer between dislocated heterointerfaces and region. The threshold current density LD was ∼20.3 kA/cm2 with lasing wavelength 444.9 nm. This demonstrates alternative approach AlInGaN...

We demonstrate a III-nitride edge emitting laser diode (EELD) grown on (2021) bulk GaN substrate with tunnel junction contact for hole injection. The was using combination of metal-organic chemical-vapor deposition (MOCVD) and ammonia-based molecular-beam epitaxy (MBE) which allowed to be regrown over activated p-GaN. For bar dimensions 1800 µm x 2.5 µm, without facet coatings, the threshold current 284 mA (6.3 kA/cm2) single slope efficiency 0.33 W/A (12% differential efficiency). A...

We report the first demonstration of III–nitride vertical-cavity surface-emitting lasers (VCSELs) with tunnel junction (TJ) intracavity contacts grown completely by metal–organic chemical vapor deposition (MOCVD). For TJs, n++-GaN was on in-situ activated p++-GaN after buffered HF surface treatment. The electrical properties and epitaxial morphologies TJs were investigated TJ LED test samples. A VCSEL a contact showed lasing wavelength 408 nm, threshold current ∼15 mA (10 kA/cm2), voltage...

We have achieved continuous-wave (CW) operation of an optically polarized m-plane GaN-based vertical-cavity surface-emitting laser (VCSEL) with ion implanted current aperture, a tunnel junction intracavity contact, and dual dielectric distributed Bragg reflector design. The reported VCSEL has 2 quantum wells, 14 nm well width, 1 barriers, 5 electron-blocking layer, 23λ total cavity thickness. thermal performance was improved by increasing the length using Au-In solid-liquid interdiffusion...

Long wavelength (525–575 nm) (112¯2) light emitting diodes were grown pseudomorphically on stress relaxed InGaN buffer layers. Basal plane dislocation glide led to the formation of misfit dislocations confined bottom layer. This provided one-dimensional plastic relaxation in film interior, including device active region. The change state quantum well due altered valence band structure, which produced a significant shift polarization emitted light. Devices buffers demonstrated equivalent...

Cathodoluminescence (CL) was used to study the onset of mechanical stress relaxation in low indium composition semipolar (112¯2) InxGa1−xN lattice-mismatched layers grown on bulk GaN substrates. Monochromatic CL short interfacial misfit dislocation (MD) segments showed a single threading (TD) associated with each MD segment—demonstrating that initial stage formation III-nitride heterostructures proceeded by bending and glide pre-existing TDs (0001) slip plane. The state coherency as...

Nominally lattice matched InAlN/GaN was grown by plasma-assisted molecular beam epitaxy, and the intrinsic microstructure investigated via x-ray diffraction, transmission electron microscopy, atom probe tomography. The InAlN showed a cellular structure, which comprised of ∼10 nm wide Al-rich cores ∼1 In-rich intercellular boundaries. Despite strong laterally non-uniform In distribution, both vertical lateral lattices are unperturbed as evidenced thickness fringes in on-axis ω−2θ high...

We investigate the bow of free standing (0001) oriented hydride vapor phase epitaxy grown GaN substrates and demonstrate that their curvature is consistent with a compressive to tensile stress gradient (bottom top) present in substrates. The origin attributed correlated inclination edge threading dislocation (TD) lines away from [0001] direction. A model proposed relation derived for bulk substrate dependence on angle density TDs. used analyze commercially available as determined by high...

By studying low radiative efficiency blue III-nitride light emitting diodes (LEDs), we find that the ABC model of recombination commonly used for understanding behavior in LEDs is insufficient and additional effects should be taken into account. We propose a modification to standard by incorporating bimolecular nonradiative term. The modified shown much better agreement with data more consistent than conventional very short carrier lifetimes measured time-resolved photoluminescence similar,...

We report strong band gap photoluminescence at room temperature in dilute quaternary GaNxAs1−x−yBiy alloys (x&amp;lt;1.6%,y&amp;lt;2.6%) grown by molecular beam epitaxy. The of the alloy can be approximated GaAs minus reduction associated with effects N and Bi alloying individually. A one-parameter method for fitting composition dependence gaps semiconductor is proposed which excellent agreement data Ga1−yInyNxAs1−x.