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

Candela‐class high‐brightness InGaN/AlGaN double‐heterostructure (DH) blue‐light‐emitting diodes(LEDs) with the luminous intensity over 1 cd were fabricated As an active layer, a Zn‐doped InGaN layer was used for the DH LEDs The typical output power was 1500 μW and the external quantum efficiency was as high as 27% at a forward current of 20 mA at room temperature The peak wavelength and the full width at half‐maximum of the electroluminescence were 450 and 70 nm, respectively This value of luminous intensity was the highest ever reported for blue LEDs

Candela‐class high‐brightness InGaN/AlGaN double‐heterostructure blue‐light‐emitting diodes

First-principles calculations have evolved from mere aids in explaining and supporting experiments to powerful tools for predicting new materials and their properties. In the first part of this review we describe the state-of-the-art computational methodology for calculating the structure and energetics of point defects and impurities in semiconductors. We will pay particular attention to computational aspects which are unique to defects or impurities, such as how to deal with charge states and how to describe and interpret transition levels. In the second part of the review we will illustrate these capabilities with examples for defects and impurities in nitride semiconductors. Point defects have traditionally been considered to play a major role in wide-band-gap semiconductors, and first-principles calculations have been particularly helpful in elucidating the issues. Specifically, calculations have shown that the unintentional n-type conductivity that has often been observed in as-grown GaN cannot be a...

First-principles calculations for defects and impurities: Applications to III-nitrides

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

In the past several years, research in each of the wide‐band‐gap semiconductors, SiC, GaN, and ZnSe, has led to major advances which now make them viable for device applications. The merits of each contender for high‐temperature electronics and short‐wavelength optical applications are compared. The outstanding thermal and chemical stability of SiC and GaN should enable them to operate at high temperatures and in hostile environments, and also make them attractive for high‐power operation. The present advanced stage of development of SiC substrates and metal‐oxide‐semiconductor technology makes SiC the leading contender for high‐temperature and high‐power applications if ohmic contacts and interface‐state densities can be further improved. GaN, despite fundamentally superior electronic properties and better ohmic contact resistances, must overcome the lack of an ideal substrate material and a relatively advanced SiC infrastructure in order to compete in electronics applications. Prototype transistors have been fabricated from both SiC and GaN, and the microwave characteristics and high‐temperature performance of SiC transistors have been studied. For optical emitters and detectors, ZnSe, SiC, and GaN all have demonstrated operation in the green, blue, or ultraviolet (UV) spectra. Blue SiC light‐emitting diodes (LEDs) have been on the market for several years, joined recently by UV and blue GaN‐based LEDs. These products should find wide use in full color display and other technologies. Promising prototype UV photodetectors have been fabricated from both SiC and GaN. In laser development, ZnSe leads the way with more sophisticated designs having further improved performance being rapidly demonstrated. If the low damage threshold of ZnSe continues to limit practical laser applications, GaN appears poised to become the semiconductor of choice for short‐wavelength lasers in optical memory and other applications. For further development of these materials to be realized, doping densities (especially p type) and ohmic contact technologies have to be improved. Economies of scale need to be realized through the development of larger SiC substrates. Improved substrate materials, ideally GaN itself, need to be aggressively pursued to further develop the GaN‐based material system and enable the fabrication of lasers. ZnSe material quality is already outstanding and now researchers must focus their attention on addressing the short lifetimes of ZnSe‐based lasers to determine whether the material is sufficiently durable for practical laser applications. The problems related to these three wide‐band‐gap semiconductor systems have moved away from materials science toward the device arena, where their technological development can rapidly be brought to maturity.

Large‐band‐gap SiC, III‐V nitride, and II‐VI ZnSe‐based semiconductor device technologies

Atmospheric pressure metalorganic vapor phase epitaxial growth and characterization of high quality GaN on sapphire (0001) substrates are reported. Using AlN buffer layers, GaN thin films with optically flat surfaces free from cracks are successfully grown. The narrowest x‐ray rocking curve from the (0006) plane is 2.70’ and from the (2024) plane is 1.86’. Photoluminescence spectra show strong near band edge emission. The growth condition dependence of crystalline quality is also studied.

Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer

Effects of ain buffer layer on crystallographic structure and on electrical and optical properties of GaN and Ga1−xAlxN (0 < x ≦ 0.4) films grown on sapphire substrate by MOVPE

Selective growth of wurtzite GaN and AlxGa1-xN on GaN/sapphire substrates by metalorganic vapor phase epitaxy

A Schottky barrier on unintentionally doped n‐type GaN grown by hydride vapor phase epitaxy was obtained and characterized. Using vacuum evaporated gold as the Schottky barrier contact and aluminum for the ohmic contact, good quality diodes were obtained. The forward current ideality factor was n∼1.03 and the reverse bias leak current below 1×10−10 A at a reverse bias of −10 V. The barrier height φBn was determined to be 0.844 and 0.94 eV by current‐voltage and capacitance measurements, respectively.

Schottky barrier on n‐type GaN grown by hydride vapor phase epitaxy

Transient capacitance methods were used to analyze traps occurring in unintentionally doped n‐type GaN grown by hydride vapor‐phase epitaxy. Studies by deep‐level transient spectroscopy (DLTS) and isothermal capacitance transient spectroscopy indicated the presence of three majority‐carrier traps occurring at discrete energies below the conduction band with activation energies (eV) ΔE1=0.264±0.01, ΔE2=0.580±0.017, and ΔE3=0.665±0.017. The single‐crystal films of GaN were grown on GaN formed by metal‐organic chemical‐vapor deposition and on sputter‐deposited ZnO; a similar deep‐level structure was found in both types of samples. Pulse‐width modulation tests using DLTS to determine the capture rates of the traps showed that the capture process is nonexponential, perhaps due to the high trap concentration. The origins of the deep levels are discussed in light of secondary‐ion‐mass‐spectroscopy analysis and group theory results in the literature.

Nobuhiko Sawaki

Papers

Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer

Effects of ain buffer layer on crystallographic structure and on electrical and optical properties of GaN and Ga1−xAlxN (0 < x ≦ 0.4) films grown on sapphire substrate by MOVPE

Selective growth of wurtzite GaN and AlxGa1-xN on GaN/sapphire substrates by metalorganic vapor phase epitaxy

Schottky barrier on n‐type GaN grown by hydride vapor phase epitaxy

Analysis of deep levels in n‐type GaN by transient capacitance methods