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

Phosphor-converted white light-emitting diodes (pc-WLEDs) are emerging as an indispensable solid-state light source for the next generation lighting industry and display systems due to their unique properties including but not limited to energy savings, environment-friendliness, small volume, and long persistence. Until now, major challenges in pc-WLEDs have been to achieve high luminous efficacy, high chromatic stability, brilliant color-rending properties, and price competitiveness against fluorescent lamps, which rely critically on the phosphor properties. A comprehensive understanding of the nature and limitations of phosphors and the factors dominating the general trends in pc-WLEDs is of fundamental importance for advancing technological applications. This report aims to provide the most recent advances in the synthesis and application of phosphors for pc-WLEDs with emphasis specifically on: (a) principles to tune the excitation and emission spectra of phosphors: prediction according to crystal field theory, and structural chemistry characteristics (e.g. covalence of chemical bonds, electronegativity, and polarization effects of element); (b) pc-WLEDs with phosphors excited by blue-LED chips: phosphor characteristics, structure, and activated ions (i.e. Ce 3+ and Eu 2+ ), including YAG:Ce, other garnets, non-garnets, sulfides, and (oxy)nitrides; (c) pc-WLEDs with phosphors excited by near ultraviolet LED chips: single-phased white-emitting phosphors (e.g. Eu 2+ –Mn 2+ activated phosphors), red-green-blue phosphors, energy transfer, and mechanisms involved; and (d) new clues for designing novel high-performance phosphors for pc-WLEDs based on available LED chips. Emphasis shall also be placed on the relationships among crystal structure, luminescence properties, and device performances. In addition, applications, challenges and future advances of pc-WLEDs will be discussed.

Phosphors in phosphor-converted white light-emitting diodes: Recent advances in materials, techniques and properties

REVIEW High-efficiency light-emitting diodes emitting amber, green, blue, and ultraviolet light have been obtained through the use of an InGaN active layer instead of a GaN active layer. The localized energy states caused by In composition fluctuation in the InGaN active layer are related to the high efficiency of the InGaN-based emitting devices. The blue and green InGaN quantum-well structure light-emitting diodes with luminous efficiencies of 5 and 30 lumens per watt, respectively, can be made despite the large number of threading dislocations (1 x 10(8) to 1 x 10(12) cm-2). Epitaxially laterally overgrown GaN on sapphire reduces the number of threading dislocations originating from the interface of the GaN epilayer with the sapphire substrate. InGaN multi-quantum-well structure laser diodes formed on the GaN layer above the SiO2 mask area can have a lifetime of more than 10,000 hours. Dislocations increase the threshold current density of the laser diodes.

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The Roles of Structural Imperfections in InGaN-Based Blue Light-Emitting Diodes and Laser Diodes

We have developed a simple approach to high-performance, stretchable, and foldable integrated circuits. The systems integrate inorganic electronic materials, including aligned arrays of nanoribbons of single crystalline silicon, with ultrathin plastic and elastomeric substrates. The designs combine multilayer neutral mechanical plane layouts and "wavy" structural configurations in silicon complementary logic gates, ring oscillators, and differential amplifiers. We performed three-dimensional analytical and computational modeling of the mechanics and the electronic behaviors of these integrated circuits. Collectively, the results represent routes to devices, such as personal health monitors and other biomedical devices, that require extreme mechanical deformations during installation/use and electronic properties approaching those of conventional systems built on brittle semiconductor wafers.

Stretchable and foldable silicon integrated circuits.

Plan-view transmission electron microscopy (TEM) and cathodoluminescence (CL) images were taken for the same sample at exactly the same location in n-type GaN grown on sapphire substrate by metalorganic chemical vapor deposition (MOCVD). There was a clear one to one correspondence between the dark spots observed in CL images and the dislocations in TEM foils, indicating that the dislocations are non-radiative recombination centers. The hole diffusion length in n-type GaN was estimated to be neighboring 50 nm by comparing the diameters of the dark spots in thick samples used for CL and samples that were thinned for TEM observation. The efficiency of light emission is high as long as the minority carrier diffusion length is shorter than the dislocation spacing.

https://iopscience.iop.org/article/10.1143/JJAP.37.L398/pdf

Direct Evidence that Dislocations are Non-Radiative Recombination Centers in GaN

The band gap energy and band lineup of 15 binary, 42 ternary and 39 quaternary III-V alloy semiconductors composed of (B, Al, Ga, In)(N, P, As, Sb) are calculated by mean of the dielectric method of Van Vechten and the Harrison model, respectively. The alloys including N are predicted to have negative band gap energy in most of the compositional range due to the large electro-negativity of nitrogen atom. Possible material combinations for a lattice-matched doubleheterostructure for blue-light-emitting devices are discussed. The chart presented here will be useful in designing blue-to-ultraviolet light emitters with and without strain in the devices

https://iopscience.iop.org/article/10.1143/JJAP.32.4413/pdf

Band gap energy and band lineup of III-V alloy semiconductors incorporating nitrogen and boron

Temperature-dependent photoluminescence (PL) measurements are performed on In0.23Ga0.77N/GaN single-quantum-well structures with different well thickness. Based on a band-tail model, the exciton localization effect is studied. The exciton localization effect is enhanced by increasing quantum-well thickness up to 2.5 nm. If the quantum-well thickness is further increased to above 2.5 nm, the exciton localization effect becomes weak. Finally, when the quantum-well thickness is increased to 5 nm, the exciton localization effect cannot be observed. In addition, the PL intensity decreases monotonically with increasing the quantum-well thickness. In connection with an excitation-power dependent PL measurement, the result of the quantum-well thickness dependent PL intensity can be attributed to quantum confined Stark effect, which becomes particularly strong in the wide quantum-well structure. Based on our optical investigation, the presented article indicates that the emission mechanism is dominated by the exci...

Influence of the quantum-well thickness on the radiative recombination of InGaN/GaN quantum well structures

A new method of reducing dislocation density in GaN layer grown on sapphire substrate by MOVPE

The exciton-localization effect and quantum-confine Stark effect (QCSE) on the performance of InGaN/GaN-based light-emitting diodes (LEDs) have been investigated with regard to indium mole fraction and well thickness by means of temperature-dependent and excitation-power-dependent photoluminescence measurements. The exciton-localization effect can be enhanced by increasing the indium mole fraction or increasing well thickness but up to 2.5 nm. The QCSE is monotonically enhanced with increasing indium concentration or well thickness. The output power of the LED can be increased by the enhanced exciton-localization effect; however, the QCSE has much stronger influence on the output power of LEDs than the exciton-localization effect, which should be taken into account for further improving the performance of InGaN/GaN-based LEDs.

Shiro Sakai

Papers

Direct Evidence that Dislocations are Non-Radiative Recombination Centers in GaN

Band gap energy and band lineup of III-V alloy semiconductors incorporating nitrogen and boron

Influence of the quantum-well thickness on the radiative recombination of InGaN/GaN quantum well structures

A new method of reducing dislocation density in GaN layer grown on sapphire substrate by MOVPE

Investigation of the emission mechanism in InGaN/GaN-based light-emitting diodes