We present a comprehensive, up-to-date compilation of band parameters for the technologically important III–V zinc blende and wurtzite compound semiconductors: GaAs, GaSb, GaP, GaN, AlAs, AlSb, AlP, AlN, InAs, InSb, InP, and InN, along with their ternary and quaternary alloys. Based on a review of the existing literature, complete and consistent parameter sets are given for all materials. Emphasizing the quantities required for band structure calculations, we tabulate the direct and indirect energy gaps, spin-orbit, and crystal-field splittings, alloy bowing parameters, effective masses for electrons, heavy, light, and split-off holes, Luttinger parameters, interband momentum matrix elements, and deformation potentials, including temperature and alloy-composition dependences where available. Heterostructure band offsets are also given, on an absolute scale that allows any material to be aligned relative to any other.

Band parameters for III–V compound semiconductors and their alloys

We present a comprehensive and up-to-date compilation of band parameters for all of the nitrogen-containing III–V semiconductors that have been investigated to date. The two main classes are: (1) “conventional” nitrides (wurtzite and zinc-blende GaN, InN, and AlN, along with their alloys) and (2) “dilute” nitrides (zinc-blende ternaries and quaternaries in which a relatively small fraction of N is added to a host III–V material, e.g., GaAsN and GaInAsN). As in our more general review of III–V semiconductor band parameters [I. Vurgaftman et al., J. Appl. Phys. 89, 5815 (2001)], complete and consistent parameter sets are recommended on the basis of a thorough and critical review of the existing literature. We tabulate the direct and indirect energy gaps, spin-orbit and crystal-field splittings, alloy bowing parameters, electron and hole effective masses, deformation potentials, elastic constants, piezoelectric and spontaneous polarization coefficients, as well as heterostructure band offsets. Temperature an...

Band parameters for nitrogen-containing semiconductors

Gallium nitride (GaN) and its allied binaries InN and AIN as well as their ternary compounds have gained an unprecedented attention due to their wide-ranging applications encompassing green, blue, violet, and ultraviolet (UV) emitters and detectors (in photon ranges inaccessible by other semiconductors) and high-power amplifiers. However, even the best of the three binaries, GaN, contains many structural and point defects caused to a large extent by lattice and stacking mismatch with substrates. These defects notably affect the electrical and optical properties of the host material and can seriously degrade the performance and reliability of devices made based on these nitride semiconductors. Even though GaN broke the long-standing paradigm that high density of dislocations precludes acceptable device performance, point defects have taken the center stage as they exacerbate efforts to increase the efficiency of emitters, increase laser operation lifetime, and lead to anomalies in electronic devices. The p...

/pdf/luminescence-properties-of-defects-in-gan-4hjs241x7f.pdf

Luminescence properties of defects in GaN

Recent research results pertaining to InN, GaN and AlN are reviewed, focusing on the different growth techniques of Group III-nitride crystals and epitaxial films, heterostructures and devices. The chemical and thermal stability of epitaxial nitride films is discussed in relation to the problems of deposition processes and the advantages for applications in high-power and high-temperature devices. The development of growth methods like metalorganic chemical vapour deposition and plasma-induced molecular beam epitaxy has resulted in remarkable improvements in the structural, optical and electrical properties. New developments in precursor chemistry, plasma-based nitrogen sources, substrates, the growth of nucleation layers and selective growth are covered. Deposition conditions and methods used to grow alloys for optical bandgap and lattice engineering are introduced. The review is concluded with a description of recent Group III-nitride semiconductor devices such as bright blue and white light-emitting diodes, the first blue-emitting laser, high-power transistors, and a discussion of further applications in surface acoustic wave devices and sensors.

https://iopscience.iop.org/article/10.1088/0022-3727/31/20/001/pdf

Growth and applications of Group III-nitrides

The optical properties of wurtzite-structured InN grown on sapphire substrates by molecular-beam epitaxy have been characterized by optical absorption, photoluminescence, and photomodulated reflectance techniques. These three characterization techniques show an energy gap for InN between 0.7 and 0.8 eV, much lower than the commonly accepted value of 1.9 eV. The photoluminescence peak energy is found to be sensitive to the free-electron concentration of the sample. The peak energy exhibits very weak hydrostatic pressure dependence, and a small, anomalous blueshift with increasing temperature.

/pdf/unusual-properties-of-the-fundamental-band-gap-of-inn-2xzjzzt783.pdf

Unusual properties of the fundamental band gap of InN

Cathodoluminescence (CL) measurements of the ground-state excitonic transition of vertically stacked $\mathrm{Ga}\mathrm{N}∕\mathrm{Al}\mathrm{N}$ quantum dots (QDs) exhibited an in-plane linear polarization anisotropy in close proximity to microcracks. Microcracks form as a result of a mismatch of the thermal expansion coefficient between the $\mathrm{Ga}\mathrm{N}∕\mathrm{Al}\mathrm{N}$ layers and the Si(111) substrate. In close proximity to the cracks, the layers are found to be under uniaxial tensile stress, whereas the film is under biaxial tensile stress for distances greater than $\ensuremath{\sim}3\phantom{\rule{0.3em}{0ex}}\ensuremath{\mu}\mathrm{m}$ from the cracks. The microcracks serve as an excellent stressor through which the strain tensor of the $\mathrm{Ga}\mathrm{N}∕\mathrm{Al}\mathrm{N}$ QDs can be reproducibly modified for studies of strain-induced changes in the optical and electronic properties by using a spatially resolved probe, such as with CL. Changes in the optical properties of the QDs are attributed to stress-dependent variations of the band edges and the electric field along [0001], which is caused by charge polarization. Such changes in the field will subsequently affect the oscillator strength between electrons and holes. Three-dimensional $6\ifmmode\times\else\texttimes\fi{}6$ $\mathbit{k}\ensuremath{\cdot}\mathbit{p}$ calculations of the QD electron and hole wave functions and eigenstates were performed to examine the influence of biaxial and uniaxial tensile stresses on the polarization-dependent momentum matrix element in varying proximity to the microcracks. The model reveals that a change from biaxial to uniaxial stress alters the admixture of ${p}_{x}$ and ${p}_{y}$ characters of the band edges and the ground-state hole wave function, changes the shape and direction of elongation of the hole isosurfaces, and accounts well for the subsequent anisotropy in the polarization dependent optical transitions.

Effect of uniaxial stress on the polarization of light emitted from Ga N ∕ Al N quantum dots grown on Si(111)

The high power RF device performance decreases as operation temperature increases ( e.g. fall of electron mobility impacting the cut-off frequencies and degradation of device reliability). Therefore the determination of device temperature is a key issue for device topology optimisation. This work presents the comparison between pulsed I - V at different temperature and DC measurements of AlGaN/GaN HEMTs grown on two different substrates: sapphire and silicon. This technique allows the determination of mean channel temperature and the device thermal resistance. The thermal resistance is a classical way to define the average channel temperature as a function of the dissipated power. In this work the thermal resistance ratio of the HEMT grown on sapphire compared to the one grown on silicon is found to be 1.7 instead of 3 as expected from straightforward thermal conductivity ratio. This lower difference is clearly attributed to the contribution of the GaN buffer layer.

Thermal characterisation of AlGaN/GaN HEMTs grown on silicon and sapphire substrates based on pulsed I-V measurements

This work presents an optical characterization by luminescence and reflectivity of GaN layers grown on sapphire using MOVPE, HVPE and GSMBE. Well resolved optical spectra are obtained for each growth technique. The luminescence of Mg doped MOVPE grown GaN is also studied. A Mg acceptor optical depth of ~ 260 meV is obtained.

/pdf/luminescence-and-reflectivity-of-gan-sapphire-grown-by-movpe-4oyynhfm3v.pdf

Luminescence and reflectivity of GaN/sapphire grown by MOVPE, GSMBE and HVPE

We discuss the temperature dependence of various photoluminescence transitions observed in undoped and doped GaN in the 9 to 300 K range. Samples grown using different techniques have been assessed. The mechanism underlying the various quenching behaviors observed is investigated using simple rate equations. In undoped GaN, the temperature dependence of the band edge excitonic lines is well described by assuming that the A exciton population is the leading term in the 50 to 300 K range. The activation energy for free exciton quenching is of the order of the Rydberg, suggesting that free hole release leads to non-radiative recombination. In slightly p-doped samples, the luminescence is dominated by acceptor-related transitions, whose intensity is also governed by release of free holes. For large p-type doping (p(300 K) greater than or equal to 10(17) cm(-3)), the activation energy for quenching is in the 60 to 90 meV range.

Temperature dependence of photoluminescence intensities of undoped and doped GaN

GaInN/GaN quantum dots (QDs) are grown by molecular beam epitaxy making use of the Stranski-Krastanov growth regime. III Situ scanning tunneling microscopy (STM) evidences the formation of three-dimensional GaInN islands. An island density as high as 10(12) cm(-2)? is deduced from STM images. It is shown that the room-temperature photoluminescence (PL) of GaInN/GaN QDs can be tuned from 3 eV to 2.5 eV by increasing the GaInN thickness from 10 to 30 A. Photothermal deflection spectroscopy is carried out to measure the absorption of GaInN/GaN QDs. For dots emitting at 2.63 eV, a Stokes shift of 250 meV is found between the maximum PL energy and the absorption edge indicating very strong carrier localization.

Jean Massies

Papers

Effect of uniaxial stress on the polarization of light emitted from Ga N ∕ Al N quantum dots grown on Si(111)

Thermal characterisation of AlGaN/GaN HEMTs grown on silicon and sapphire substrates based on pulsed I-V measurements

Luminescence and reflectivity of GaN/sapphire grown by MOVPE, GSMBE and HVPE

Temperature dependence of photoluminescence intensities of undoped and doped GaN

Strong carrier localization in GaInN/GaN quantum dots grown by molecular beam epitaxy