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

Light emitting diodes (LEDs) based on In(x)Gal(1-x)N (x = 0.15-0.2)/GaN multiple-quantum wells ( MQWs) have been grown on sapphire substrates. Their wavelength emission can be tuned from blue to orange by increasing the QW thickness. This opens the way for monolithic white LEDs by combining several QWs of various thicknesses, i.e., "colors", inside the GaN p-n junction. This is demonstrated by the realization of white (blue + yellow) dual color LEDs. The coordinates in the CIE 1931 chromaticity diagram of the EL spectrum are (x = 0.29, y = 0.31) and correspond to a color temperature of 8000 K. The expected performances of the monolithic white LEDs are compared to hybrid technologies such as blue LEDs pumping yellow phosphors.

https://iopscience.iop.org/article/10.1143/JJAP.40.L918/pdf

Monolithic White Light Emitting Diodes Based on InGaN/GaN Multiple-Quantum Wells

We show that optical reflectivity measurements can be used to evaluate the part of a NH3 flux which reacts with a Ga-terminated GaN surface or with a Ga-flux simultaneously impinging on the surface, as in standard molecular beam epitaxy situation. At least for temperatures not exceeding 700 °C, the ratio of the reacted part of the NH3 flux to the incident flux can be assimilated to the NH3 cracking efficiency. Being nearly zero below a threshold temperature of 450 °C, it increases with temperature but remains low (∼4%) explaining why an exceptionally high V/III flux ratio is necessary to grow GaN using NH3.

Efficiency of NH3 as nitrogen source for GaN molecular beam epitaxy

Dislocation-free high-quality AlGaN/GaN heterostructures have been grown by molecular-beam epitaxy on semi-insulating bulk GaN substrates. Hall measurements performed in the 300 K–50 mK range show a low-temperature electron mobility exceeding 60 000 cm2/V s for an electron sheet density of 2.4×1012 cm−2. Magnetotransport experiments performed up to 15 T exhibit well-defined quantum Hall-effect features. The structures corresponding to the cyclotron and spin splitting were clearly resolved. From an analysis of the Shubnikov de Hass oscillations and the low-temperature mobility we found the quantum and transport scattering times to be 0.4 and 8.2 ps, respectively. The high ratio of the scattering to quantum relaxation time indicates that the main scattering mechanisms, at low temperatures, are due to long-range potentials, such as Coulomb potentials of ionized impurities.

/pdf/high-electron-mobility-in-algan-gan-heterostructures-grown-m3miob1iaw.pdf

High Electron Mobility in AlGaN/GaN Heterostructures Grown on Bulk GaN Substrates

We report on the growth of high-electron-mobility AlGaN/GaN heterostructures on silicon (111) substrates by molecular-beam epitaxy using ammonia as the nitrogen source. Crack-free GaN layers up to 3 μm are obtained. Their optical properties are similar to those commonly obtained for films grown on sapphire, but photoluminescence spectra indicate that GaN on Si(111) is in a tensile strain state which increases with the epitaxial layer thickness. Such uncracked GaN buffer layers grown on Si(111) have been used to achieve undoped AlGaN/GaN heterostructures having electron mobilities exceeding 1600 cm2/V s at room temperature and 7500 cm2/V s at 20 K.

High-electron-mobility AlGaN/GaN heterostructures grown on Si(111) by molecular-beam epitaxy

InGaN/GaN self-assembled quantum dots (QDs) were obtained by molecular beam epitaxy making use of the Stranski–Krastanov growth mode. Room-temperature photoluminescence (PL) energy of QDs was observed from 2.6 to 3.1 eV depending on the dot size. PL linewidths as low as 40–70 meV at 10 K and 90–110 meV at 300 K indicate low dot size dispersion. The comparison of PL intensity versus temperature of an InGaN epilayer and InGaN/GaN QDs demonstrates the higher radiative efficiency of the latter.

Jean Massies

Papers

Monolithic White Light Emitting Diodes Based on InGaN/GaN Multiple-Quantum Wells

Efficiency of NH3 as nitrogen source for GaN molecular beam epitaxy

High Electron Mobility in AlGaN/GaN Heterostructures Grown on Bulk GaN Substrates

High-electron-mobility AlGaN/GaN heterostructures grown on Si(111) by molecular-beam epitaxy

Room-temperature blue-green emission from InGaN/GaN quantum dots made by strain-induced islanding growth