Long-Wavelength LEDs in the Atmospheric Transparency Window of 4.6–5.3 μm

Semiconductors - 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...     

Stimulated Emission in the 1.3–1.5 μm Spectral Range from AlGaInAs Quantum Wells in Hybrid Light-Emitting III–V Heterostructures on Silicon Substrates

Semiconductors - Hybrid laser structures with AlGaInAs quantum wells are grown by metalorganic vapor phase epitaxy on Ge/Si(100) “virtual” substrates using GaAs and InP buffer layers....     

InGaAs/AlGaAs QWIP Heterostructures for Large-Format Focal Plane Arrays Photosensitive in the Spectral Range 3–5 μm

Photoelectric properties of different stressed InGaAs/AlGaAs heterostructures with quantum wells grown by the method of molecular beam epitaxy on GaAs substrates for mid-wavelength infrared largeformat photodetector arrays operating in the spectral range 3–5 μm have been investigated. It has been shown that the change in the composition of barrier layers leads to a significant shift of the photosensitivity spectra of such heterostructures.     

Study of the Auger Recombination Energy Threshold in a Series of Waveguide Heterostructures with HgTe/Cd0.7Hg0.3Te QWs Near 14 μm

Semiconductors - Stimulated emission from a heterostructure with Hg0.903Cd0.097Te/Cd0.7Hg0.3Te quantum wells, placed in a waveguide layer of wide-gap CdHgTe, is obtained at wavelengths of...     

Continuous-Wave Stimulated Emission in the 10–14-μm Range under Optical Excitation in HgCdTe/CdHgTe-QW Structures with Quasirelativistic Dispersion

Semiconductors - In two waveguide heterostructures with quantum-well arrays of Hg0.892Cd0.108Te/Cd0.63Hg0.37Te with a thickness of 6.1 nm and Hg0.895Cd0.105Te/Cd0.66Hg0.34Te with a thickness of 7.4...     

Photodiodes for Detecting the Emission of Quantum-Sized Disc Lasers Operating in the Whispering Gallery Modes (2.2–2.3 μm)

Semiconductors - Photodiodes based on solid solutions in the GaSb–InAs system are for the first time applied to study the spectral characteristics of single and coupled...     

320 × 240 CMOS array for the spectral range of 3–5 μm based on PtSi photodiodes

The results of research and development of a 320 × 240 platinum silicide focal plane array (FPA) for the spectral range of 3–5 μm are presented. The development is based entirely on CMOS technology. It is shown that the FPA makes it possible to adjust the photosignal accumulation time at a fixed frame rate and subtract the background constant component in the output device.     

Spectral-kinetic properties of heterostructures with GaAsSb/InGaAs/GaAs-based quantum wells emitting in the range of 1.0–1.2 μm

The spectral-kinetic properties of heterostructures with GaAs/GaAsSb-based and GaAsSb/InGaAs/GaAs-based quantum wells, emitting in the range of 1.0–1.2 μm are studied with picosecond and nanosecond temporal resolution. Intense photoluminescence in the GaAsSb/InGaAs/GaAs structure, as well as an increase in the photoluminescence wavelength by a factor of 2.5 and a shift of the location of the maximum of the peak (～100 meV) to the longer-wavelength region were observed up to room temperature. It is established that as the molar fraction of Sb and the thickness of the InGaAs layer increase, the energy of the fundamental transition decreases by a factor of 140 meV compared with the GaAsSb/InGaAs/GaAs structure with a lower Sb content and a smaller thickness of the InGaAs layer. At 300 K, the emission wavelength of such a structure was 1.18 μm. In addition, an increase in the thickness of the InGaAs layer led to an increase in the room-temperature photoluminescence intensity by a factor of 60, which is associated with a decrease in the energy of the fundamental state for electrons in the InGaAs layer and, consequently, to larger electron localization and smaller temperature quenching of photoluminescence.     

Uncooled Photodiodes for Detecting Pulsed Infrared Radiation in the Spectral Range of 0.9–1.8 μm

Semiconductors - Uncooled photodiodes based on GaSb/GaAlAsSb heterostructures for recording pulsed infrared radiation in the spectral range of 0.9–1.8 μm are developed and studied. The...     

Temperature dependence of the threshold current in quantum-well WGM lasers (2.0–2.5 μm)

The temperature dependence of the threshold current and emission spectra of disk-shaped quantum-well whispering-gallery mode (WGM) lasers is studied in the temperature range of 80–463 K in which the laser emission wavelength increases from 2 to 2.5 μm. It is shown that lasing is observed up to 190°C. Radiative recombination is dominant up to a temperature of 300 K, and nonradiative Auger recombination, in which a recombining electron gives energy to another electron, is so at higher temperatures. The spin-orbit split-off valence subband is not involved in recombination processes, which is attributed to mechanical compression of the quantum-well material.     

Investigation of the Current–Voltage Characteristics of New MnO2/GaAs(100) and V2O5/GaAs(100) Heterostructures Subjected to Heat Treatment

Semiconductors - Complex oxide films with a thickness of about 200 nm are formed during the thermal oxidation of GaAs with magnetron-deposited V2O5 and MnO2 nanolayers. The electrical parameters of...     

Independent operation time of photodetectors of the (3—5)-μm spectral band based on InSb and CdHgTe heteroepitaxial structures

The time of independent operation t _ind of indium antimonide photoresistors and photodiodes and photoresistors based on Cd _х Hg_1–х Te (х ~ 0.3) heterostructures deeply cooled with a Joule–Thomson throttling system is investigated. The largest independent operation time (taut ≥ 28 s) was obtained for Cd _х Hg_1–х Te (х ~ 0.3) photoresistors. Time t _ind of the photoresistors and photodiodes is found to be related to the temperature of transition of the semiconductor materials from the impurity region to the intrinsic region. The possibility of increasing time t _ind of the photodetectors by optimizing the requirements for the characteristics of InSb and Cd _х Hg_1–х Te is discussed.     

Light emitting diodes for the spectral range of λ=3.3–4.3 μm fabricated from the InGaAs-and InAsSbP-based solid solutions: Electroluminescence in the temperature range of 20–180°C

Light emitting diodes (LEDs) with λ_max=3.4 and 4.3 µm (t=20°C) were studied at elevated temperatures. It is demonstrated that LEDs operating in the temperature range t=20–180°C can be described using the classical concepts of injection radiation sources and the processes of charge carrier recombination. The temperature dependences of reverse currents in the saturation regions of current-voltage characteristics are consistent with the increase in the intrinsic-carrier concentration according to the Shockley theory. The emission spectra are described on the assumption of the direct band-to-band transitions, spherically symmetric bands, and thermalized charge carriers. The current-power characteristics are proportional to I ^3/2 suggesting that the contribution of the nonradiative Auger recombination is dominant. The radiation power decreases exponentially with the temperature which is characteristic of the CHSH and CHCC processes.     

Effect of Ce2O3 on the 1.53 μm spectroscopic properties in Er3+-doped tellurite glasses

The crown-like zinc oxide(Zn O)samples,which are composed of a hexagonal cap and a tower-like shaft,are prepared by vapor transport method.The hexagonal cap,working as a whispering gallery mode(WGM)resonant cavity,demonstrates density-dependent ultraviolet(UV)lasing emission with a broadened and squared photoluminescence(PL)profile under UV excitation at 355 nm.Theoretical analyses based on Fermi golden rule show that the broadened spectrum profile results from the special optical mode density characteristics in a WGM micro-cavity,which is in agreement with the observed results.     

Effect of Ce2O3 on the 1.53 μm spectroscopic properties in Er3+-doped tellurite glasses

Er3+/Ce3+co-doped tellurite-based glasses with composition of TeO 2-Zn O-Na2O are prepared by high-temperature melt-quenching technique.Effects of Ce2O3 content on the 1.53μm band fluorescence spectra and fluorescence lifetime of Er3+are measured and investigated.It is found that the tellurite glass containing Ce2O3 with molar concentration of 0.25%exhibits an increment of 13%in 1.53μm fluorescence intensity and an increment of 15%in the 4I13/2 level lifetime.The results indicate that the prepared tellurite-based glass with a suitable Er3+/Ce3+codoping concentration is an excellent gain medium applied for broadband Er3+-doped fiber amplifier(EDFA)pumped with a980 nm laser diode.     

High-speed photodiodes for the mid-infrared spectral region 1.2–2.4 μm based on GaSb/GaInAsSb/GaAlAsSb heterostructures with a transmission band of 2–5 GHz

High-speed p-i-n photodiodes for the spectral range of 1.2–2.4 μm are fabricated for the first time based on a GaAs/GaInAsSb/GaAlAsSb heterostructure with separated sensitive-(50 μm in diameter) and contact mesas, which are connected by a bridge front contact. The use of an unconventional design for the contact mesa with a Si₃N₄ insulating sublayer 0.3 μm thick under the metal contact made it possible to lower both the intrinsic photodiode capacitance and the reverse dark currents. The photodiodes have a low intrinsic capacitance of 3–5 pF at zero bias and 0.8–1.5 pF at a reverse bias of 3.0 V. The photodiode operating speed, which is determined by the time of increasing the photoresponse pulse to a level of 0.1–0.9, is 50–100 ps. The transmission band of the photodiodes reaches 2–5 GHz. The photodiodes are characterized by low reverse dark currents I _d = 200–1500 nA with a reverse bias of U = ?(0.5–3.0) V, a high current monochromatic sensitivity of R _i = 1.10–1.15 A/W, and a detectability of D*(λ_max, 1000, 1) = 0.9 × 10¹¹ W^?1 cm Hz^1/2 at wavelengths of 2.0–2.2 μm.     

InAsSb/InAsSbP double-heterostructure lasers emitting in the 3–4 µm spectral range

Our earlier reports concerning the fabrication by liquid-phase epitaxy and investigation of InAsSbP/InAsSb/InAsSbP double heterostructure lasers emitting at 3–4 μm are reviewed. The dependences of spectral characteristics and the spatial distribution of the laser emission on temperature and current are discussed. Lasing modes are shifted by 0.5–1.0 cm⁻¹ to longer wavelengths with increasing temperature. The tuning of the lasing modes by means of current is very fast (10⁻⁸–10⁻¹² s). With increasing current, the modes are shifted to shorter wavelengths by 50–60 ? at 77 K. The maximum mode shift of 104 ? (10 cm⁻¹) is observed at 62 K. The spectral line width of the laser is as narrow as 10 MHz. Abnormally narrow directional patterns in the p-n junction plane are observed in some cases in the spatial distribution of laser emission. The current tuning of lasers, due to nonlinear optical effects, has been modeled mathematically in good agreement with the experiment. Transmittance spectra of OCS, NH₃, H₂O, CH₃Cl, and N₂O gases were recorded using current-tuned lasers. __________ Translated from Fizika i Tekhnika Poluprovodnikov, Vol. 35, No. 12, 2001, pp. 1466–1480. Original Russian Text Copyright ? 2001 by Danilova, Imenkov, Kolchanova, Yakovlev. See [1].     

Excitonic Effects and Impurity–Defect Emission in GaAs/AlGaAs Structures Used for the Production of Mid-IR Photodetectors

Semiconductors - A series of undoped GaAs/AlxGa1 –xAs multiple quantum well heterostructures, whose doped analogs are used for the production of photodetectors operating in the spectral range...     

IR photodetectors in the range of λ = 1.5–8 μm, based on silicon with multicharged nanoclusters of manganese atoms

It is demonstrated that infrared photodetectors based on silicon with multicharged nanoclusters of manganese atoms can be designed that operate in the wavelength range of ?? = 1.55?C8 ??m. Photodetectors fabricated on such materials have the following parameters: a spectral sensitivity range of ?? = 1.55?C8 ??m, an operating temperature range of T = 77?C250 K, an optimal electric field of E = 5 V/cm, an optimal size of V = 3 × 2 × 1 mm³, a sensitivity threshold of S = 10^?9 W/cm², and a response time of ?? < 10^?6 s.