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The n+-InAs/n0-InAs1 –ySby/p-InAsSbP heterostructures with asymmetric band offsets at the heteroboundaries of the active region have been grown by vapor-phase epitaxy from organometallic compounds on InAs substrates. The forward branch of the current–voltage characteristics of the obtained heterostructures at low temperatures has segments with the tunneling conduction. The energy-band diagram of the double InAs/InAs1 –ySby/InAsSbP heterostructure is calculated in the range of compositions (y < 0.2) of the narrow-gap active region. The InAs1 –ySby/InAsSbP heterojunction is shown to be a II type heterojunction in this composition range. The electroluminescence observed in the experiment for the n+-InAs/n0-InAs1 ‒ySby/p-InAsSbP heterostructures with the active region in compositions y > 0.14 is due to interface radiative transitions with participation of localized hole states at the II type heteroboundary. [ABSTRACT FROM AUTHOR]

The peculiarity of planar quantum magnetotransport in the type II broken-gap p-GaInAsSb/p-InAs heterostructures at high magnetic fields has been investigated. The structure of the hybridized energy spectrum of a two-dimensional semimetal channel at a single type II broken-gap heterointerface was considered in dependence on the composition of the quaternary solid solution. A transition from a conducting state to a dielectric state (quantum insulator) for a 2D-semimetal channel at the heteroboundary was observed in quantizing magnetic fields under the condition of simultaneous filling of the first Landau levels for 2D-electron and interface hole states. [ABSTRACT FROM AUTHOR]

Mid-infrared photoluminescence has been observed from interface transitions in high quality, abrupt P–Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78]/p-InAs heterojunctions grown by liquid phase epitaxy from an In-rich melt. The Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78] quaternary epitaxial layer was unintentionally doped and grown lattice matched on to a (100) oriented p-type InAs substrate, resulting in a P–p isotype heterojunction. The photoluminescence emission spectra were investigated and exhibited three pronounced emission bands in the spectral region from 0.30 to 0.68 eV; hν[sub 1]=0.317 eV, hν[sub 2]=0.380 eV, and hν[sub L]=0.622 eV. The emission band hν[sub 1] was identified with radiative transitions between electron and hole quantum well subbands in the semimetal channel at the P–GaIn[sub 0.03]As[sub 0.10]Sb/p-InAs interface, while the hν[sub 2] band originates from radiative transitions involving deep acceptor states in the InAs substrate. The high-energy recombination hν[sub L] is characteristic of the Ga[sub 0.84]In[sub 0.16]As[sub 0.22]Sb[sub 0.78] bulk quaternary layer. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

This overview is devoted to the discovery, development of the technology, and investigation of III–V semiconductors performed at the Ioffe Institute, where the first steps in fabricating III–V semiconductors were taken in 1950 and investigations into their fundamental properties were begun under the leadership of two outstanding scientists—Nina Aleksandrovna Goryunova and Dmitry Nikolayevich Nasledov. Further development of these investigations is reflected in the works of followers and pupils of D.N. Nasledov, who have worked and continue to work at subsidiaries of the Ioffe Institute. The contribution of these investigations to studying heterostructures based on III–V compounds as well as to the development of semiconductor devices for electronics, optoelectronics, and photonics is considered. [ABSTRACT FROM AUTHOR]

The authors studied the features of planar and vertical quantum magnetotransport in the broken-gap type II p-GaInAsSb/p-InAs heterostructure. This study reveals the structure of the hybridized energy spectrum of a two-dimensional semi-metallic channel at a single broken-gap type II heterointerface. It is demonstrated that an energy diagram of Landau levels can be visualized for a hybridized electron-hole system taking into account their spin splitting and mutual intersections. [ABSTRACT FROM AUTHOR]

Abstract: Characteristic effects of magnetic ordering and conduction in semiconductor heterostructures with a GaAs : Be/Ga0.84In0.16As/GaAs quantum well and manganese δ-layers of different thickness (from 0.4 to 2 monolayers) were studied based on analysis of magnetic field and temperature dependences, galvanomagnetic effects, and magnetization. An anomalous dependence of the conductivity on the manganese atoms concentration in the δ-layer was observed, which was due to a strong scattering of charge carriers in the structures with the low content of magnetic impurities. Magnetic properties of the heterostructures clearly indicated the magnetic ordering of the impurity system (saturation and hysteresis of the magnetization and fulfillment of the Curie-Weiss law at increasing temperature). Parameters of the magnetic subsystem allowed revealing different types of ordering in the systems with different concentrations of the magnetic impurity. Changing the concentration of the Mn admixture in the δ-layer was shown to influence significantly the conductivity and magnetism in the studied structures. [ABSTRACT FROM AUTHOR]

The effect of the interface roughness (IFR) scattering on the carrier mobility in type II broken-gap p-GaInAsSb/p-InAs heterostructures with self-consistent quantum wells at the interface has been studied experimentally. It was found that the low-temperature mobility decreases as μ∼d2 when the quantum well width at the interface changes from 400 to 50 Å upon raising the acceptor (Zn) doping level of the quaternary layer. It was established that the IFR scattering governs the low-temperature mobility in the two-dimensional electron channel at the heterointerface. The parameters of the IFR scattering, roughness height Δ=12 Å, and correlation length Λ=100 Å were evaluated on the basis of structural, photoluminescent, and magnetotransport data. [ABSTRACT FROM AUTHOR]

Layers of the GaSb1 − x As x alloy with arsenic content in the range x = 0.06–0.15 have been grown for the first time on InAs (100) substrates by metal-organic vapor-phase epitaxy. A new approach to the calculation of the band diagram of the GaSbAs alloy is suggested. It is demonstrated on the basis of magnetotransport measurements in p-GaSbAs/ p-InAs heterostructures and with the method suggested by the authors for the calculation of band diagrams for alloys in the GaSbAs system that, in the composition range under study, the GaSbAs/InAs heterojunction is a type II broken-gap heterojunction. [ABSTRACT FROM AUTHOR]

The lasing of an injection-pumped p-AlGaAsSb/n[SUP0]-InAs/n-CdMgSe double hybrid heterostructure in the mid-IR range is demonstrated for the first time. The lasing wavelength λ is 2.775 μm, and the threshold current density J[SUBth] = 3-4 kA/cm[SUP2] at T = 77 K. The structure grown by two-stage molecular-beam epitaxy is characterized by extremely high (∼1.5 eV) asymmetric potential barriers for electrons and holes in the InAs active region. The output power of spontaneous emission for round-mesa diodes atT = 300 K was no less than 0.3 mW. [ABSTRACT FROM AUTHOR]

High-quality type II Ga[sub 0.83]In[sub 0.17]As[sub 0.22]Sb[sub 0.78]/InAs heterostructures based on GaSb-rich quaternary solid solutions were grown by liquid phase epitaxy on InAs(001) substrates. GaInAsSb epilayers were grown under planar two-dimensional growth conditions with abrupt and planar interfaces. The thickness of the transition layer on the Ga[sub 0.83]In[sub 0.17]As[sub 0.22]Sb[sub 0.78]/InAs interface enriched with In and Sb was 10-12 Å in perfect structures. The roughness of the upper boundary was entirely determined by the epitaxial-growth conditions and did not exceed 500 Å in structures with a layer thickness of about 2 µm. [ABSTRACT FROM AUTHOR]

Electroluminescence bistability is observed in a typ-II P-AlGaAsSb/p-InGaAsSb/ N-AlGaAsSbheterostructure with lightly doped cladding layers and a narrow-gap active region (the width of the band gap is E[sub g]= 326 meV at the temperature T = 77 K). A currentcontrolled negative differential resistance is observed in the forward branch of the currentvoltage characteristic. Strong narrowband electroluminescence (half-width ∼ 7 - 10 meV) is observed at the end of the negative differential resistance interval, where the photon energy at the radiation maximum exceeds the width of the band gap of the narrow-gap material by 50 meV. This phenomenon is attributed to the tunneling injection and indirect radiative recombination of carriers localized at the AlGaAsSb/InGaAsSb heterojunction. As the voltage is increased, radiative transitions in the bulk of the active region begin to provide the main contribution, and the radiation maximum jumps to the long-wavelength end. Tunneling injection structures of this kind can be used to construct highly efficient current-controlled lightemitting diodes. [ABSTRACT FROM AUTHOR]

Intense electroluminescence is observed for the first time in a AlGaAsSb/In[sub 0.9]Ga[sub 0.1]As[sub 0.89]Sb[sub 0.21]/ AlGaAsSb double heterostructure in the 3-4 µm wavelength range at T=77 K. The structure was grown on a GaSb substrate by liquid-phase epitaxy. The photon energy at the maximum of the narrow emission band with a half-width of 9-10 eV is h ν, = 387 meV which is 60 meV greater than the band gap of the narrow-gap InGaAsSb solid solution (E[sub g]= 326 meV). [ABSTRACT FROM AUTHOR]

Asymmetric n-InAs/InAs(1 –y)Sby/p-InAsSbP heterostructures with a narrow-gap active layer and a composition range y = 0.09–0.16 were grown by vapor phase epitaxy from metalorganic compounds. Room-temperature electroluminescence was observed at a wavelength of up to λ = 5.1 μm at a spectral maximum. The study of low-temperature electroluminescence spectra provided the possibility to establish the existence of two radiative recombination channels caused by the nature of the InAsSb/InAsSbP heterointerface. The effect produced by the chemistry of the active layer on the composition of the grown barrier layer and the formation of the InAsSb/InAsSbP heterojunction with an increase in the antimony content in the InAsSb solid solution was demonstrated. [ABSTRACT FROM AUTHOR]

The electroluminescent characteristics of the InAs/InAs1–ySby/InAsSbP asymmetric light-emitting diode heterostructures with high InSb mole fraction in the active region (y > 0.09) in the temperature range 4.2–300 K have been studied. Stimulated emission was achieved in the wavelength range 4.1–4.2 μm at low temperatures (T < 30 K). It was found that the electroluminescence spectra were formed as a result of the superposition of contributions from different channels of radiative recombination of charge carriers near the type II heterointerface. The effect of the quality of the type II InAsSb/InAsSbP heterojunction on the radiative interface transitions with an increase in the content of InSb in the ternary solid solution is considered. [ABSTRACT FROM AUTHOR]

New possibilities of scanning electron microscopy, using secondary- and reflected-electron signals, for determining the position of heteroboundaries in long-wavelength laser structures are reported. The formation of the indicated signals in structures of mid-infrared-range lasers of a new type based on type-II GaInAsSb/InGaAsSb heterostructures as well as in the conventional InAsSb/InAsSbP heterostructures is analyzed. The observed characteristic features of the formation of secondary- and reflected-electron signals in these structures as compared with the well-studied AlGaAs/GaAs structures are explained. The results obtained are necessary for accurate determination of an important laser parameter — the position of the p-n junction. It is shown that it is best to use the reflected-electron signal. [ABSTRACT FROM AUTHOR]

A study of the electroluminescence of asymmetric InAs/InAs1 – ySby/InAsSbP light-emitting diode heterostructures with a molar fraction of InSb in the ternary solid solution in the active region y = 0.15 and y = 0.16 in the temperature range 4.2–300 K is reported. It is found on the basis of experimental data that a staggered type-II heterojunction is formed at the InAs1 – ySby/InAs0.41Sb0.28P0.40 heterointerface. It is shown that interfacial radiative transitions at the type-II heterointerface make a dominant contribution in the temperature range of 4.2–180 K. This enables minimization of the temperature dependence of the operating wavelength of a light-emitting diode. [ABSTRACT FROM AUTHOR]

The design and technology for the fabrication of an asymmetric stepped InAs/InAs1 –ySby/InAsSbP heterostructure with an ultimate InSb content (up to y = 0.17) in the narrow-gap active region by vapor-phase epitaxy from metal-organic compounds are developed. The electroluminescence characteristics of long-wavelength LEDs based on the proposed heterostructure, which emits in the spectral range of 4.6–5.3 μm, are studied. A linear decrease in the quantum efficiency of the electroluminescence with increasing InSb content in the active layer of the LEDs obtained is revealed. The advantage of using the asymmetric heterostructure for fabricating LEDs with a working wavelength of more than 4.5 μm is shown. [ABSTRACT FROM AUTHOR]

A hybrid double heterostructure with large asymmetric band offsets, combining AlAsSb/InAs (as a III-V part) and CdMgSe/CdSe (as a II-VI part), has been proposed as a basic element of a midinfrared laser structure design. The p-i-n diode structure has been successfully grown by molecular beam epitaxy and has exhibited an intense long-wavelength electroluminescence at 3.12 μm (300 K). A less than 10 times reduction of electroluminescence intensity from 77 to 300 K indicates an efficient carrier confinement in the InAs active layer due to high potential barriers in conduction and valence bands, estimated as ΔE[sub C]=1.28 eV and ΔE[sub V]∼1.6 eV. The type of band lineups at a coherent InAs/Cd[sub 1-x]Mg[sub x]Se interface is discussed for 0≤x≤0.15. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Ga0.84In0.16As0.22Sb0.78 quaternary solid solutions, lattice matched to InAs, were grown by liquid phase epitaxy on (100)-oriented p-InAs substrates from In-rich melt. The p-type Ga0.84In0.16As0.22Sb0.78 layers were intentionally undoped or slightly doped with Sn to the hole concentration about p∼5×1016 cm-3. This allowed us to obtain a high-mobility∼(3.5-5.0)×104 cm2 V-1 s-1 electron channel at the type II broken-gap p-Ga0.84In0.16As0.22Sb0.78/p-InAs heterointerface. Low-temperature (T=5 K) electroluminescence spectra exhibited two pronounced emission bands hν1=0.372 eV and hν2=0.400 eV under forward bias. The emission band hν2 was split into two lines and was attributed to interband transitions through acceptor and valence-band states in the bulk InAs, whereas emission band hν1 was ascribed to interface-related radiative transitions of electrons from the two-dimensional electron channel to the interface states at the p-Ga0.84In0.16As0.22Sb0.78/p-InAs heteroboundary. [ABSTRACT FROM AUTHOR]

The results of detailed study of the magnetotransport properties of broken-gap type II heterojunctions in a GaInAsSb/InAs(GaSb) system are reported. An electron channel with a high charge-carrier mobility (as high as 50000–60000 cm2/(V s)) is observed and studied for the first time in an isotype broken-gap p-GaInAsSb/ p-InAs heterostructure. The effects of electron-channel depletion and semimetal-semiconductor transition in the case of heavy doping of the quaternary alloy with acceptors are studied. Magnetotransport properties at temperatures of 4.2–200 K are studied in detail. Data on the energy spectrum and parameters of two-dimensional charge carriers at the heteroboundary are obtained. It is ascertained experimentally that, depending on the composition, either staggered (at x = 0.85) or broken-gap (at x = 0.95) heterojunctions can be formed in the Ga1− x InxAsySb1− y /GaSb, which is confirmed by theoretical calculations. The anomalous Hall effect and negative magnetoresistance were observed in GaInAsSb/InAs:Mn grown on substrates doped heavily with Mn magnetic acceptor impurity so that the hole concentration was as high as p > 5 × 1018 cm−3; these phenomena are caused by exchange interaction of Mn ions in InAs with high-mobility charge carriers in the electron channel at the heterointerface. [ABSTRACT FROM AUTHOR]

Specific features of the energy spectrum of a separated type-II heterojunction in an external magnetic field are studied theoretically and experimentally. It is shown that, due to hybridization of the states of the valence band of one semiconductor and the conduction band of the other semiconductor at the heterointerface, there are level anticrossings, which produce quasigaps in the density of states in a nonzero magnetic field. The experimental results of magnetotransport studies for the GaInAsSb/p-InAs quaternary solid solutions with different doping levels are shown to agree well with the results of simulation, and specific features of the energy spectrum of separated type-II heterojunctions are established. © 2004 MAIK “Nauka / Interperiodica”. [ABSTRACT FROM AUTHOR]

Current-tunable diode lasers with narrow emission lines for laser spectroscopy in the 3.2-3.4 µm wavelength range are developed. The lasers, based on an InAsSb/InAsSbP double heterostructure, have a widestripe cavity. The wave number increases from 3030 to 3034 cm[sup -1] as the current is raised from 1.5 to 3 times the threshold value at 70 K, while the full width at half-maximum of the laser line decreases from 18 to 10 MHz. It is demonstrated that the linewidth is determined by fluctuations of the cavity resonance frequencies as a result of fluctuations in the concentration of nonequilibrium charge carriers. [ABSTRACT FROM AUTHOR]

The results of a comparative study of the temperature dependence of the threshold current, the differential quantum efficiency, and the polarization of light are reported for type-I and type-II InAsSb/InAsSbP heterostructures and for a tunneling injection laser utilizing a type-II GalnAsSb/InGaAsSb separate-confinement heterojunction. The theoretically predicted suppression of nonradiative Auger recombination in type-II InAsSb/InAsSbP lasers with a large ratio of band discontinuities at the interface ΔE[sub v]/ΔE[sub c] = 3.4 is verified experimentally. Weakening of the temperature dependence of the threshold current is established for both type-II laser configurations. The maximum working temperatures T[sub lim] = 203 and 195 K and the characteristic temperatures T[sub 0] = 40 and 47 K are attained for (respectively) a conventional type-II InAsSb/InAsSbP laser and a type-II p-GaInAsSb/n-InGaAsSb tunneling injection laser. [ABSTRACT FROM AUTHOR]

A mid-IR laser based on a hybrid pseudomorphic AlGaAsSb/InAs/CdMgSe heterostructure with a III-V/II-VI heterovalent interface at the 0.6-µm-InAs active region has been fabricated by molecular-beam epitaxy on p[sup +]-InAs substrate. It provides ∼1.5-eV asymmetric barriers for both electrons and holes in InAs, inhibiting carrier leakage from the active region. Despite a nonoptimal defect density at the CdMgSe/InAs interface (10[sup 6]-10[sup 7] cm[sup -2]), the structure demonstrates lasing at ∼2.78 µm (up to 100 K) under pulse injection pumping with the threshold current density of 3-4 kA/cm². The proposed design is promising for high-power mid-IR lasers operating at room temperature. [ABSTRACT FROM AUTHOR]

The electroluminescence of the single unconfined type-II heterojunction p-GaInAsSb/p-InAs was investigated in the temperature range T = 4.2-77 K. As the temperature was reduced below T = 77 K, the luminescence bands with maxima at 311 meV (band A) and 384 meV (band B) were found to shift toward higher energies. At 4.2 K, the short-wave band split into two bands, B[sub 1] and B[sub 2]. These results are explained in terms of a model involving recombinations of electrons from the conduction band to an acceptor level of InAs, and also recombinations of electrons and holes localized in self-consistent quantum wells on either side of the heterojunction. [ABSTRACT FROM AUTHOR]

The electroluminescence appearing upon pulsed excitation in a solitary p-GaInAsSb/p-InAs typeII (broken-gap) heterostructure is investigated at T = 77 K. It is shown that just as in the case of excitation by a constant current, two emission bands with maxima corresponding to 384 and 311 meV, respectively, are observed in the spectra. The half-widths of the emission bands equal 18-19 meV. Time-resolved spectroscopy is used to evaluate the relaxation time of the nonequilibrium carriers, which amounts to 6-7 µs. The emission spectrum is calculated on the basis of the Kane model, and the radiative recombination time is estimated. The theoretical estimates are in reasonable agreement with experiment. [ABSTRACT FROM AUTHOR]

An investigation is carried out on the properties of the electron channel in a broken-gap isotypic type II GaInAsSb/p-InAs heterostructure and their dependence on the doping level of the quaternary solid solution with a donor (Te) and an acceptor (Zn). The Hall mobility decreases (by more than two orders of magnitude) with increasing acceptor concentration. The Shubnikov-de Haas oscillations are observed at low temperatures (T = 1.5-20 K) and the electron effective mass is determined (m[sub n] = 0.026m[sub 0]), along with some other parameters of the heterostructure. [ABSTRACT FROM AUTHOR]