Yury P. Yakovlev

Semiconductor lasers and photodiodes for gas analysis in the spectral range 1.8-2.5 μm

Semiconductor lasers and photodiodes for the 1.8-2.5 micron spectral range are described which can be used in gas analysis systems. The characteristics of pulsed lasers with output optical power reaching 1 W and low-threshold single-mode lasers are presented. The photodiodes have high quantum efficiency (0.6 without antireflection coating) and high speed or response (0.5 ns at reverse bias of several volts).

Semiconductor WGM lasers for the mid-IR spectral range

Disk-cavity whispering-gallery-mode (WGM) semiconductor lasers for the mid-IR spectral range have been developed. The specific properties of these devices are investigated.

Optoelectronic LED-photodiode pairs for moisture and gas sensors in the spectral range 1.8-4.8 um

Optoelectronic light-emitting diode-photodiode pairs based on multicomponent GaInAsSb and InAsSbP solid solutions have been researched and developed. Such pairs are able to detect absorption bands of water and gases belonging to the spectral range 1.8 - 4.8 micrometers (H2O, CO, CO2, H2S, N2O, CH4, etc.). Two-wavelength models of a new type of optical moisture meter and a methane meter was fabricated using the developed LEDs and high-efficiency photodiodes.

Electroluminescence of confined carriers in type II broken-gap p-GaInAsSb/p-InAs single heterojunction

First observation of electroluminescence in type II broken-gap p-GaInAsSb/p-InAs single heterojunctions is reported. Intensive spontaneous emission was obtained under applied bias at T equals 77 - 300 K. Two narrow `resonant emission bands were observed in the spectral range 3 - 5 micrometers at T equals 77 K with full width at half maximum about 1 - 2 kT. It was established that effect of unusual electroluminescence in isotype type II broken-gap p-p- heterostructure due to indirect (tunnel) radiative recombination of spatial separated 2D- electrons and holes localized in deep adjacent quantum wells at different sides of the interface. Novel tuneable mid-infrared light sources are proposed.

Interface luminescence and lasing at a type II single broken-gap heterojunction

We have proposed a new physical approach for the design of mid-IR lasers operating at λ = 3.2 - 3.26 μm based on type II heterojunctions with a large asymmetric band-offset at the interface (ΔEC > 0.6 eV and ΔEV > 0.35 eV). These high potential barriers produce effective electron-hole confinement at the interface and results in a tunnel-injection radiative recombination mechanism within the device due to reduce leakage current from the active region. The creation of high barriers for carriers leads to their strong accumulation in the active region and increases quantum emission efficiency of the spatially separated electrons and holes across the heteroboundary. Our approach also leads to the suppression of non-radiative Auger-recombination and a corresponding increase in the operation temperature of the laser. The active region of the laser structure consists of the type II heterojunction formed by narrow-gap In0.83Ga0.17As0.82Sb0.18 (Eg = 0.393 eV at 77 K) and wide-gap Ga0.84In0.16As0.22Sb0.78 (Eg = 0.635 eV at 77 K) layers lattice-matched to InAs substrate.

Linewidth of GaInAsSb diode lasers

The linewidth of GaInAsSb diode lasers operating at 1.8-2.4 micron has been measured using gas absorption line as a frequency discriminator. The linewidth of the lasers varied from 3 to 60 MHz, could alter at least by an order of magnitude, and decrease as the temperature decreases and emission power increases. The results show that GaInAsSb lasers are suitable for high-resolution molecular spectroscopy.

Low-noise GaInAsSb/GaAlAsSb SAM avalance photodiode in the 1.6-2.5μm spectral range

GalnAsSb/GaAlAsSb SAM APDs were fabricated and investigated.nThe GaAlAsSb solid solution of the resonant composition (x=0.04, Eg = ?0 ) was used in the multiplication region of the devices. Large ionization rate ratio (?/? =60) and low excess noise factor ( F=Mf f=0.2) was experimentally observed.

Tunneling recombination of carriers at type-II interface in GaInAsSb-GaSb heterostructures

We report the first observation of the carriers confinement and recombination in the nadjusted quantum wells at the type II interface in GaInSbAs/GaSb heterostructures grown by nliquid phase epitaxy. nType II heterostructures in which both the conduction and the valence band edges of one nsemiconductor are shifted upward relative to those of the other one can exhibit adjacent dual nquantum wells for electrons and holes on the two sides of the interface. Tunneling-assisted nradiative recombination between the wells offers an efficient, bias-tunable, source of radiation at nbelow-gap energies.

Type-II heterojunctions in GaSb-InAs solid solutions: physics and applications

Staggered-lineup type II heterojunctions have been realized in Ga In As Sb solid solutions lattice matched. to GaSb as well as ones depending on alloy composition (x1 O. 23 or XinO8O)i n Unique features of type II heterojunctions due to carrier localization and spatial separation on the interface have been experixnen tally observed by electroluminescence generation of coherent radiation and photocurrent gain. Distinctive hallmarks of the narrow-gap GaSbGaInAsSb heterojunctions have been considered in connection with CV 1-. V and spectral response experiments. Energy band schemes of such structures have been analized. GaSbGaInAsSb heterojunctions with x 0. 80 were found to be type II misaligned ones. Novel optoelectronic devices for midIR spectral range of 1 (lasers LIDs and high-. speed photodiodes) were developed on the base of GaSb-GaInAsSb heterojunctions.

New semiconductor material A1xInAsySb/InAs: LPE synthesis and properties

The phase diagram of the quaternary AlInAsSb system has been investigated. These data have been used for LPE growth of the AlxIn1-xAsySb1-y solid solutions lattice-matched to InAs (with Al mole percentage in the range 0.0-0.08). A band gap was determined for this material in dependence on the composition by photoluminescence measurements. The band gap of the solid solution in the investigated range of composition corresponds to a wavelength from 3 micrometers (x equals 0.0, Eg equals 0.414 eV) to 2.5 micrometers (x equals 0.08, Eg equals 0.49 eV).