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In this paper, the problem of depth profiling analysis of nanoscale heterostructures containing doped delta layers and quantum wells using the SIMS method is considered. Based on computer simulation data and previously obtained experimental data, we demonstrated that the RMR model most accurately and completely describes the redistribution of the analyzed element in ultrathin layers that occurs during ion sputtering. A comparative analysis of the surface roughness–ion mixing–recoil implantation (RMR) model with MRI (mixing-roughness-information depth) and UDS (up-and-down slope) models proposed by Hoffman and Dowsett, respectively, was performed. It was shown that the introduction into the MRI model of a parameter describing some layer of constant thickness, in which the components of the analyzed layer and matrix elements are uniformly mixed, is not quite justified. It is concluded that during depth profiling of a monoatomic layer, the center of mass of this layer shifts away from the surface, as predicted by the RMR model, rather than toward the surface, as predicted by the MRI model. It is found that preferential sputtering does not affect the experimental depth distribution of elements obtained by the SIMS method. [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]

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]

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]

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]

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]

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]

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]