Effect of postgrowth techniques on the characteristics of triple-junction InGaP/Ga(In)As/Ge solar cells

The photoelectric characteristics of triple-junction InGaP/Ga(In)As/Ge solar cells are studied in relation to the method used to form the photocell chip. It is shown that the application of a postgrowth technique developed in the study for separating a nanoheterostructure into chips in a single process makes it possible to improve the quality of passivation of the chip edges, which diminishes the surface leakage currents and makes larger the yield of devices with improved characteristics.     

Heterostructures of Single-Wavelength and Dual-Wavelength Quantum-Cascade Lasers

The results of development of the basic structure and technological conditions of growing heterostructures for single- and dual-frequency quantum-cascade lasers are reported. The heterostructure for a dual-frequency quantum-cascade laser includes cascades emitting at wavelengths of 9.6 and 7.6 μm. On the basis of the suggested heterostructure, it is possible to develop a quantum-cascade laser operating at a difference frequency of 8 THz. The heterostructures for the quantum-cascade laser are grown using molecularbeam epitaxy. The methods of X-ray diffraction and emission electron microscopy are used to study the structural properties of the fabricated heterostructures. Good agreement between the specified and realized thicknesses of the epitaxial layers and a high uniformity of the chemical composition and thicknesses of the epitaxial layers over the area of the heterostructure is demonstrated. A stripe-structured quantum-cascade laser is fabricated; its generation at a wavelength of 9.6 μm is demonstrated.     

Molecular beam epitaxy of thermodynamically metastable GaInAsSb alloys for medium IR-range photodetectors

Semiconductors - The features of growth of GaInAsSb alloy with In content as high as 25 mol % lattice-matched to GaSb by molecular beam epitaxy are studied. These alloys are promising for use as...     

Anomalous electron spin splitting in InAs pumped by injection

The electroluminescence and photoluminescence of bulk n-InAs with a high concentration of donors (N _d ≈ 5 × 10¹⁶ cm^?3) is studied experimentally in magnetic field in the Faraday layout of the experiment. Under the conditions of electrical injection, the photon energy corresponding to the electroluminescence peak exceeds the energy band gap E _g. When a magnetic field is applied, the energy of the peak becomes lower than E _g, and the peak splits into two circular-polarized components. The splitting depends on the injection current. In moderate magnetic fields (about 2 T), the splitting can be much more profound than the calculated splitting corresponding to the well-known g factor of electrons in InAs. The effect is attributed to different degrees of magnetic freezing-out of electrons with different spin orientation. The maximum in the dependence of the degree of polarization of photoluminescence on the magnetic field and the behavior of the photoluminescence line width support the model suggested.     

Mode-Locked Lasers with “Thin” Quantum Wells in 1.55 μm Spectral Range

Technical Physics Letters - We present the results of an experimental study of two-section semiconductor lasers with active region consisting of three 3.1 nm InGaAs/InGaAlAs quantum wells. Passive...     

Array of InGaAsSb light-emitting diodes (λ = 3.7 μm)

Spectral, current-voltage, and light-current characteristics of p-InAsSbP/n-InGaAsSb/n ⁺-InAs narrow-gap diode structures with 130 × 130 μm lateral dimensions of active elements are presented. The 2D distribution of light emitted by the samples fabricated in the form of emitting flip-chip 1 × 4 arrays is examined, including analysis of the emission uniformity. The limiting effective temperature created by an emitter of this type is determined.     

On the gain properties of “thin” elastically strained InGaAs/InGaAlAs quantum wells emitting in the near-infrared spectral region near 1550 nm

The results of experimental studies of the gain properties of “thin” (3.2 nm thick) elastically strained InGaAs/InGaAlAs quantum wells emitting in the near-infrared spectral region near 1550 nm are presented. The results of studying the threshold and gain characteristics of stripe laser diodes with active regions based on “thin” quantum wells with a lattice–substrate mismatch of +1.0% show that the quantum wells under study exhibit a high modal gain of 11 cm^–1 and a low transparency current density of 46 A/cm² per quantum well.