Long-wavelength light-emitting diodes (λ=3.4–3.9 µm) based on InAsSb/InAs heterostructures grown by vapor-phase epitaxy

InAs/InAs_0.93Sb_0.07/InAs heterostructures were grown by metal-organic vapor-phase epitaxy in a horizontal reactor at atmospheric pressure. Based on the obtained structures, light-emitting diodes operating at λ=3.45 μm (T=77 K) and λ=3.95 μm (T=300 K) were fabricated. The room-temperature quantum efficiency of light-emitting diodes was 0.12%. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 34, No. 12, 2000, pp. 1462–1467. Original Russian Text Copyright ? 2000 by Zotova, Kizhaev, Molchanov, Popova, Yakovlev.     

Lattice-matched GaInPAsSb/InAs structures for devices of infrared optoelectronics

It is reported that a Ga_0.92In_0.08P_0.05As_0.08Sb_0.87 quinary solid solution, which is lattice-matched to InAs, with a band gap of 695 meV (77 K) and 640 meV (300 K) is obtained. It is demonstrated that a heterojunction of type II is realized in the InAs/Ga_0.92In_0.08P_0.05As_0.08Sb_0.87 structure. The solid solution obtained was used for the development of prototypes of light-emitting diodes and photodiodes with the highest intensity of emission and photosensitivity in the vicinity of 1.9 µm.     

Sources of spontaneous emission based on indium arsenide

The results obtained for light-emitting diodes based on heterostructures that contain InAs in the active region and are grown by the methods of liquid-phase, molecular-beam, and vapor-phase epitaxy from organometallic compounds are reviewed. The emission intensity, the near-field patterns, and the light-current and current-voltage characteristics of light-emitting diodes that have flip-chip structure or feature a point contact are analyzed.     

Characterization of light-emitting diodes based on InAsSbP/InAsSb structures grown by metal-organic vapor-phase epitaxy

Light-emitting diodes for the wavelength range λ=3.3–4.5 µm were fabricated on the basis of InAsSbP/InAsSb heterostructures grown by metal-organic vapor-phase epitaxy. The use of vapor-phase epitaxy made it possible to appreciably increase the phosphorus content in barrier layers (up to 50%) in comparison with that attainable in the case of liquid-phase epitaxy; correspondingly, it was possible to improve confinement of charge carriers in the active region of the structures. Photoluminescent properties of InAsSb layers, electroluminescent properties of light-emitting diodes, and dependences of the emission power on current were studied. Two types of light-emitting diodes were fabricated: (i) with extraction of emission through the substrate (type A) and (ii) with extraction of emission through the epitaxial layer (type B). The light-emitting diodes operating in the pulse mode (with a relative pulse duration of 20) had an emission power of 1.2 mW at room temperature.     

Luminescence properties of InAs layers and p-n structures grown by metallorganic chemical vapor deposition

The luminescence properties of p-and n-type InAs layers grown by gas-phase epitaxy from metallorganic compounds at atmospheric pressure are investigated. Acceptor levels in InAs are identified with energies 350, 372, 387, and 397 meV. Optimal conditions are determined for the growth of InAs layers in a reactor of planetary type. At a growth temperature of 565 °C, InAs structures were obtained with abrupt p-n junctions. The structures grown were used to make light-emitting diodes operating at wavelengths of 3.1 μm (T=77 K) and 3.7 μm (T=300 K). Fiz. Tekh. Poluprovodn. 33, 1168–1172 (October 1999)     

Electrofax®printing with gallium phosphide diodes

Experimental green-light-emitting GaP diodes are shown to be capable of adequately exposing Electrofax^®paper with exposures of 400 µs. The diodes used were prepared from nitrogen-doped epitaxial junction material; the Electrofax paper was sensitized with a rose-bengal dye. Linear arrays of seven diodes spaced 250 µm apart have been constructed and used to print characters on a moving strip of Electrofax paper developed by a reversal liquid toner system. Measured image resolution is better than 40 elements/cm. Data are given on the electrical characteristics of a single diode and an array, and on the dependence of image density and dimensions on diode currents. The observed performance of the diodes indicates the feasibility of making a high-quality printer using light-emitting diodes (LED's) and Electrofax paper.     

Optically pumped mid-infrared InGaAs(Sb) LEDs

Spectral and power characteristics of optically pumped light-emitting diodes (LEDs) for the 3.1–3.6 µm range are presented. The LED structure contains narrow-gap InGaAs or InGaAsSb layers on an n ⁺-InAs substrate; the pumping is done with a GaAs LED. A conversion efficiency of 90 mW/(A cm²), comparable with that for injection LEDs, is achieved.     

Properties of GaSb-based light-emitting diodes with chemically cut substrates

Light-emitting diodes for the mid-IR (λ=1.7–1.9 μm) spectral range were studied. The substrate of GaSb-based light-emitting chips was chemically cut into a conical-pyramidal shape, and the number of chip faces increased from six to ten. Studies of the emission spectra and far-field pattern have shown that chemical cutting raises the external quantum efficiency and makes the far-field pattern almost hemispherical. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 37, No. 12, 2003, pp. 1465–1472. Original Russian Text Copyright ? 2003 by Grebenshchikova, Imenkov, Zhurtanov, Danilova, Chernyaev, Vlasenko, Yakovlev.     

Optically pumped “immersion-lens” infrared light emitting diodes based on narrow-gap III–V semiconductors

Spectral and power characteristics of light emitting diodes (LEDs) for the 3.3-to 7-µm range with GaAs LED pumping are presented. The LEDs consist of narrow-gap In(Ga)As, InAsSb(P), or InAs layers on a n ⁺-InAs substrate (band width ～λ_max/10) or on InSb (band width ～ 1 µm). The LEDs equipped with an immersion lens exhibit a conversion efficiency as high as 0.08–3 mW/A, which is comparable to or exceeds the highest reported data for the injection LEDs.     

Junction-current-confinement planar light-emitting diodes and optical coupling into large-core diameter fibers using lenses

High-radiance AlGaAs-GaAs double-heterostructure light-emitting diodes utilizing junction current confinement are described. Diode resistance and junction ideality factor are investigated as a function of emission diameters from 10 to 75 µm. Near-field intensity profiles indicate tight current confinement over the full range of emission diameters. Rise-time measurements are consistent with a simple carrier lifetime model for >25-µm emission diameters. An effective radiative-recombination constant, B = 1.5(±0.5) × 10-¹⁰cm³/s is deduced from the rise-time data and model. Peak wavelength and spectral width data are discussed in terms of junction current density and temperature. With decreasing emission diameter, the optical coupling efficiencies into 100- and 200-µm core diam high-numerical-aperture fibers increased from 10 to 25 percent and 25 to 50 percent, respectivley, using spherical glass lenses.     

Broad-band superluminescent light-emitting diodes incorporating quantum dots in compositionally modulated quantum wells

We propose and demonstrate a technique for tailoring the emission bandwidth of /spl sim/1.3 /spl mu/m quantum dot superluminescent light-emitting diodes. A broadening of the emission is achieved by incorporating the InAs quantum dot layers in InGaAs quantum wells of different indium compositions. These structures exhibit a broader and flatter emission compared to a simple dot-in well structure comprised of wells of identical indium composition.     

High-power InAs/InAsSbP heterostructure leds for methane spectroscopy (λ ≈ 3.3 μm)

Two designs of light-emitting diodes (LEDs) based on InAsSbP/InAs/InAsSbP double hetero-structures grown by metal-organic vapor phase epitaxy on p− and n-InAs substrates have been studied. The current-voltage and electroluminescence characteristics of the LEDs are analyzed. It is shown that the LED design with a light-emitting crystal (chip) mounted with the epitaxial layer down on the LED case and emission extracted through the n-InAs substrate provides better heat removal. As a result, the spectral characteristics remain stable at increased injection currents and the quantum efficiency of radiative recombination is higher. The internal quantum efficiency of light-em itting structures with an emission wavelength λ = 3.3–3.4 μm is as high as 22.3%. The optical emission power of the LEDs is 140 μW at a current of 1 A in the quasi-continuous mode and reaches a value of 5.5 mW at a current of 9 A in the pulsed mode.     

Optimized design and fabrication of high-speed and high-radiance InGaAsP/InP DH LED in the 1-µm wavelength region

Design and fabrication of an InGaAsP/InP double-heterostructure (DH) light-emitting diode (LED) with a monolithic lens, Which exhibits high-speed and high-radiance performance, have been presented. Dependences of operating characteristics such as the coupled power, the current-light linearity and the cutoff frequency on the LED, and the fiber structural parameters, have been analyzed, modeled, and applied to complete an optimal design. It has been found that a high magnification lens allows one to maximize both the coupled output power and the response speed. LED'S coupled to 50-µm core 0.2-NA graded-index fiber have been fabricated at the wavelengths of 1.15, 1.3, and 1.5 µm. A significant improvement has been achieved particularly in the cutoff frequency, and the maximum value of 120 MHz at the current of 100 mA has been realized at 1.3-µm wavelength without reduction of the coupled power (35 µW). High-speed and high-power performances of these diodes are promising for their application to high bit-rate transmission systems.     

Comparison of InGaSb/InAs superlattice structures grown by MBE on GaSb, GaAs, and compliant GaAs substrates

This paper contains the characterization results for indium arsenide/indium gallium antimonide (InAs/InGaSb) superlattices (SL) that were grown by molecular beam epitaxy (MBE) on standard gallium arsenide (GaAs), standard GaSb, and compliant GaAs substrates. The atomic force microscopy (AFM) images, peak to valley (P-V) measurement, and surface roughness (RMS) measurements are reported for each sample. For the 5 μm×5 μm images, the P-V heights and RMS measurements were 37 ? and 17 ?, 12 ? and 2 ?, and 10 ? and 1.8 ? for the standard GaAs, standard GaSb, and compliant GaAs respectively. The high resolution x-ray diffraction (HRXRD) analysis found different 0^th order SL peak to GaSb peak spacings for the structures grown on the different substrates. These peak separations are consistent with different residual strain states within the SL structures. Depending on the constants used to determine the relative shift of the valance and conduction bands as a function of strain for the individual layers, the change in the InAs conduction band to InGaSb valance band spacing could range from +7 meV to −47 meV for a lattice constant of 6.1532 ?. The cutoff wavelength for the SL structure on the compliant GaAs, control GaSb, and control GaAs was 13.9 μm, 11 μm, and no significant response, respectively. This difference in cutoff wavelength corresponds to approximately a −23 meV change in the optical gap of the SL on the compliant GaAs substrate compared to the same SL on the control GaSb substrate.     

Indium Arsenide-Based Spontaneous Emission Sources (Review: a Decade Later)

Semiconductors - The results of investigations of light-emitting diodes based on heterostructures with an InAs active region grown by liquid phase and metalorganic vapor-phase epitaxy over the last...     

On the internal quantum efficiency and carrier ejection in InGaAsP/InP-based quantum-well lasers

The optimization of InGaAsP/InP quantum-well laser heterostructures that had various configurations and emitted in the wavelength range from 1.26 up to 1.55 µm was carried out with the aim of maximizing the internal quantum efficiency and output optical power. It was experimentally shown that the heterolasers based on the laser structure with a broadened three-step waveguide have the highest quantum efficiency of stimulated radiation. In heterolasers of the suggested configuration, a decrease in the electron ejection out of the active region into the waveguide was observed. The power of the optical radiation of 4.2 W in a continuous-wave lasing mode was obtained in laser diodes with a mesa-stripe width of 100 µm. The quantum efficiency was 85% for the internal optical losses of 3.6 cm^?1.     

Light-Emitting Diodes Based on an Asymmetrical InAs/InAsSb/InAsSbP Double Heterostructure for CO2 (λ = 4.3 μm) and CO (λ = 4.7 μm) Detection

Semiconductors - Asymmetrical double InAs/InAsSb/InAsSbP heterostructures are grown by metalorganic vapor phase epitaxy. Two types (A and B) of light-emitting diodes with wavelengths of 4.1 and 4.7...     

Infrared light-emitting diodes based on GaInAsSb solid solutions grown from lead-containing solution-melts

Light-emitting diodes (LEDs) were fabricated on the basis of GaInAsSb alloys grown from lead-containing solution-melts. Electroluminescence characteristics and their current and temperature dependences were studied. The external photon yield at room temperature was 1.6 and 0.11% for LEDs with emission wavelengths λ=2.3 and 2.44 μm, respectively. For LEDs with emission wavelength λ=2.3 μm, the average emission power P=0.94 mW was attained in the quasi-continuous mode at room temperature. In the pulsed mode, the peak radiation power was P=126 mW at a current of 3 A, a pulse duration of 0.125 μs, and a frequency of 512 Hz. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 38, No. 12, 2004, pp. 1466–1472. Original Russian Text Copyright ? 2004 by Astakhova, Grebenshchikova, Ivanov, Imenkov, Kunitsyna, Parkhomenko, Yakovlev.     

Structural and optical properties of InAs quantum dots in AlGaAs matrix

Structural and optical properties of InAs quantum dots (QDs) grown in a wide-bandgap Al_0.3Ga_0.7As matrix is studied. It is shown that a high temperature stability of optical properties can be achieved owing to deep localization of carriers in a matrix whose band gap is wider than that in GaAs. Specific features of QD formation were studied for different amounts of deposited InAs. A steady red shift of the QD emission peak as far as ∼1.18 μm with the effective thickness of InAs in Al_0.3Ga_0.7As increasing was observed at room temperature. This made it possible to achieve a much higher energy of exciton localization than for QDs in a GaAs matrix. To obtain the maximum localization energy, the QD sheet was overgrown with an InGaAs layer. The possibility of reaching the emission wavelength of ~1.3 μm is demonstrated. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 37, No. 5, 2003, pp. 578–582. Original Russian Text Copyright ? 2003 by Sizov, Samsonenko, Tsyrlin, Polyakov, Egorov, Tonkikh, Zhukov, Mikhrin, Vasil’ev, Musikhin, Tsatsul’nikov, Ustinov, Ledentsov.     

Interfacial luminescence in an InAs/InAsSbP isotype type II heterojunction at room temperature

Interfacial luminescence on a single type II heterointerface in the InAs/InAsSbP system at room temperature is observed for the first time. It is confirmed experimentally that a single InAs/InAsSbP hetero-structure is a staggered type II heterojunction. The formation of an electron channel at the heterointerface on the n-InAs side in the n-InAs/n-InAsSbP heterostructure does not lead to the emergence of the radiative interfacial luminescence, while the p-InAs/p-InAsSbP heterostructure under the reverse bias manifests the interfacial luminescence caused by radiative transitions of holes from the occupied surface states localized at the heterointerface. The discovery of an intense interfacial luminescence comparable with bulk luminescence in intensity opens novel opportunities for the design of multicolor light-emitting diodes and integrated opto-electronic matrices for the mid-IR range of 3–5 μm.