InGaAs（P）／InP应变量子阱和超晶格的光电性质

利用低压金属有机化合物化学汽相沉积（ＭＯＣＶＤ）生长技术在ＩｎＰ衬底上生长ＩｎＧａＡｓ／ＩｎＰ应变量子阱，超晶格和ＩｎＧａＡｓＰ／ＩｎＰ量子阱结构材料，利用７７Ｋ光荧光（ＰＬ）测量这一应变量了阱和量子阱的光学性质，利用双晶Ｘ光测量应变超晶格的性质。     

Layer selective disordering by photoabsorption-induced thermal diffusion in InGaAs/InP based multiquantum well structures

Laser-induced intermixing of a buried InGaAs/InGaAsP multiquantum well structure using a CW Nd:YAG laser, operating at a wavelength of 1064 nm, has been demonstrated. The process does not involve transient melting of the semiconductor, but relies on preferential absorption by the active region producing sufficient heat to cause intermixing between the wells and barriers. Photoluminescence measurements at 77 K indicate that bandgap shifts as large as 123 meV are obtainable using moderate laser beam power densities and periods of irradiation.<>     

Polarization-independent field-induced absorption-coefficientvariation spectrum in an InGaAs/InP tensile-strained quantum well

The authors report the absorption-coefficient variation of a tensile-strained InGaAs/InP quantum well measured throughout the spectral range near and away from the bandgap. They discuss the spectral absorption-coefficient variation spectra of an unstrained, a 0.15%, a 0.30%, and a 0.45% tensile-strained quantum well and show that the difference between the wavelengths of absorption-coefficient variation peaks for TE and TM modes becomes zero with 0.3% tensile strain. It is shown that this wavelength difference varies linearly with the magnitude of the strain     

InGaAs/InP heterobipolar transistors for integration on semi-insulating InP substrates

InGaAs/InP npn heterojunction bipolar transistors (HBTs) have been fabricated from LPE layers grown on semi-insulating InP substrates for application to integrated circuits. The inverted emitter configuration is used, which allows the growth of the active layers without any additional steps. The HBTs show stable characteristics without any hysteresis and with current gains up to 25 for 0.7 ?m base width. To our knowledge this is the first report of InGaAs/InP HBTs on a semi-insulating substrate.     

Electron properties of surface InGaAs/InAlAs quantum wells with inverted doping on InP substrates

The electron-transport and optical properties of heterostructures with a surface InGaAs/InAlAs quantum well in the cases of inverted δ doping with Si atoms (below the quantum well) and of standard δ doping (above the quantum well) are compared. It is shown that, in the case of inverted doping, the two-dimensional electron density in the quantum well is increased in comparison with the case of the standard arrangement of the doping layer at identical compositions and thicknesses of other heterostructure layers. The experimentally observed features of low-temperature electron transport (Shubnikov–de Haas oscillations, Hall effect) and the photoluminescence spectra of heterostructures are interpreted by simulating the band structure.     

MOVPE InGaAs/InP grown directly on GaAs substrates

We have demonstrated the feasibility of growth of InP/InGaAs structures directly on GaAs using atmospheric pressure metal organic vapour phase epitaxy. Growth conditions and the equipment used are described along with some preliminary measurements on the GaAs/InP/InGaAs wafers. P-N junctions were formed in these materials to evaluate diode characteristics.     

1.27 /spl mu/m metamorphic InGaAs quantum well lasers on GaAs substrates

Pulsed operation at a wavelength of 1.27 /spl mu/m from metamorphic ridge-waveguide (RWG) InGaAs quantum well lasers on GaAs substrates using an alloy graded buffer, grown by molecular beam epitaxy, is demonstrated. Laser performance is anisotropic along the two orthogonal <1/spl plusmn/10> directions with lower threshold currents along the <1-10> direction. Post-growth rapid thermal annealing further reduces threshold currents. For 4 /spl mu/m-wide RWG lasers, minimum threshold current densities are 1-2.5 kA/cm/sup 2/ for cavity lengths 0.6-1.5 mm.     

Strained InGaAs quantum well lasers grown on

The growth by molecular beam epitaxy (MBE) of AlGaAs/GaAs/InGaAs strained quantum well lasers on GaAs     

LPE growth of InP/InGaAs/InP DH wafers on (100) InP substrates

An InP/InGaAs/InP double heterostructure wafer is grown directly on a (100) InP substrate using very low temperature LPE growth. This crystal exhibits a thin transition layer at a InP-InGaAs interface because of dissolution of the ternary layer.     

Anisotropic electroabsorption and optical modulation in InGaAs/InAlAs multiple quantum well structures

The first measurements to be made of large anistropic electroabsorption and modulation of long-wavelength light propagating along the plane of InGaAs/InAlAs multiple quantum well (MQW) structures grown by molecular beam epitaxy (MBE) are reported. Photocurrent response of waveguide p-i-n diodes is studied for incident light polarization parallel and perpendicular to the MQW layers. Photocurrent increase with reverse bias throughout the entire photoresponse spectrum is observed for both polarizations. The MQW p-in optical modulator shows a capacitance-limited pulse response of 250 ps and the modulation depth is 14 percent.     

Gas-Source molecular beam epitaxy and characterization of inGaAs/lnGaAsP quantum well structures on InP

In this paper, we report the effect of using a group-V residual source evacuation (RSE) time on the interfaces of InGaAs/lnGaAsP quantum wells (QWs) grown by gas-source molecular beam epitaxy. High-resolution x-ray rocking curve and low-temperature photoluminescence (PL) were used to characterize the material quality. By optimizing the RSE time, a PL line width at 15K as narrow as 6.6 meV is observed from a 2 nm wide single QW, which is as good as or better than what has been reported for this material system. Very sharp and distinct satellite peaks as well as Pendellosung fringes are observed in the x-ray rocking curves of In_xGa_1−xAs/InxGa_1−xAS_yP_1−y multiple QWs, indicating good crystalline quality, lateral uniformity, and vertical periodicity. Theoretical considerations of the PL linewidths of In_xGa_1−xAs/InxGa_1−xAS_yP_1−y single QWs show that for QW structures grown with the optimized RSE time, the PL linewidth is mainly due to alloy scattering, whereas the contribution from interface roughness is small, indicating a good interface control.     

Relative intensity noise reduction in InGaAs/InP multiple quantum well lasers with low nonlinear damping

The authors demonstrate theoretically and experimentally that the relative intensity noise (RIN) of laser diodes can be dramatically reduced by decreasing nonlinear damping in the laser. Four types of InGaAs/InP multiple quantum well (MQW) lasers with different well widths, barrier widths, and numbers of wells were fabricated. By comparing these four types of devices, it is shown that MQW lasers with wider wells, narrower barriers, and larger numbers of wells have smaller nonlinear damping and lower RIN.<>     

Growth and characterization of n-type InP/InGaAs quantum well infrared photodetectors for response at 8.93 µm

We present experimental results on the growth and characterization of n-type InGaAs/InP quantum-well intersubband photodetectors for use at 8.93 μm. High-quality InGaAs/InP multiple quantum wells were grown by gas source molecular beam expitaxy, and then characterized by double-crystal x-ray diffraction and cross-sectional transmission electron microscopy. Based upon the structural parameters determined by these methods, the photocurrent response spectra were simulated using a six-band effective bond-orbital model. The theoretical results are in excellent agreement with experimental data. Additional important device characteristics such as dark current, spectral response, and absolute responsivity are also presented.     

Growth and characterization of totally relaxed InGaAs thick layers on strain-relaxed paramorphic InP substrates

In this paper, we present a technological process that can be used to prepare strain-relaxed InAsP/InGaAs bilayer membranes, 0.8% lattice mismatched to InP substrates, with diameters up to 300 μm. It is shown that high-quality thick In_0.65Ga_0.35As layers can be grown fully relaxed on these membranes, without any structural defect, as demonstrated by atomic force microscopy (AFM), transmission electron microscopy (TEM), and photoluminescence (PL) characterizations. The critical thickness of InAs layers grown on InAs_0.25P_0.75 templates is enhanced from 15 ? to 60 ? when compared to InP substrates.     

High-energy and recombination-induced electroluminescence ofInAlAs/InGaAs HEMT's lattice-matched to InP substrates

We report room-temperature measurements of the high-energy electroluminescence (EL) of InAlAs/InGaAs HEMT's lattice-matched to InP substrates. We found that both the carrier temperature and the intensity obtained from the EL signal for the 1.4-1.7 eV energy range drastically increases with increasing the variation in the potential at the drain edge in the channel. The observed features are consistent with the results of the spatial distribution measurement, which indicates that the EL comes from the drain edge. We further compared the bias-voltage dependence of the high-energy EL and the recombination-induced EL measured for the same device, and discussed the origin and the threshold energy of the respective luminescent processes     

Effect of structural parameters on InGaAs/InAlAs 2DEG transport characteristics

The effect of structural parameters on the transport characteristics from 15 to 300 K of molecular beam epitaxy-grown InGaAs/InAlAs two dimensional electron gas structures lattice-matched to InP is determined. The InAlAs buffer layer thickness was varied from 1000 to 10,000Å. One sample also incorporated a InGaAs/InAlAs superlattice. The buffer layer thickness and structure had almost no effect on the mobility or sheet density. The InAlAs spacer layer was varied from 25 to 200Å. Increases in the InAlAs spacer thickness resulted in a monotonically decreasing sheet density and a peak in the mobility versus spacer thickness at 100Å. The highest 77 K mobility was 66,700 cm²/V/sds withN _D =1.2×10¹² cm^?2. The effect of illumination and temperature on the sheet concentration in these structures as well as on “bulk” InAlAs:Si was much smaller than in Al _x Ga_1?x As/GaAs structures or “bulk” Al _x Ga_1?x As, forx?0.30, indicating that devices based on this material system will not be characterized by many of the device instabilities observed in the AlGaAs/GaAs system.     

Metal-semiconductor-metal demultiplexing waveguide photodetectors in InGaAs/GaAs quantum well structures by selective bandgap tuning

A two-wavelength demultiplexing metal-semiconductor-metal (MSM) waveguide photodetector has been fabricated using impurity-free vacancy diffusion and partial intermixing of an InGaAs/GaAs strained layer quantum well structure. The importance of growth and process parameters, such as aluminium composition in the cladding layer and the oxygen plasma treatment of the sample during processing, on the related device performance is discussed. This photodetector is a potential candidate for monolithic integration with other optoelectronic devices.<>     

Investigations on the interface abruptness in CBE-grown InGaAs/InP QW structures

In this work we present a detailed analysis of chemical beam epitaxy-grown (CBE) InGaAs/InP multi quantum well (MQW) interfaces to explain experimental data from high quality single and multi-QWs. Our results compare well with the best published data we have obtained some outstanding results. For example, the very intense absorption peak and the high number of satellite peaks in the diffraction rocking curve, were obtained even on samples grown in non-optimized conditions. A careful use of growth interruption at the interfaces allows us to obtain monolayer (ml) interfaces. Nevertheless, the switching of the group V element at each interface leads to strain formation. This effect could become dramatic in superlattice structures with periods smaller than about 5 nm and barriers of less than 3–4 nm. More generally, the conditions for the growth of high quality single and multiple QWs is discussed in this work and these will be correlated with fourier transform photoluminesence (FTPL), high resolution x-ray diffraction (HRXRD), absorption, photo-absorption and photo-current (in PIN structures) measurements.     

Dependence of Hooge parameter of InAs heterostructure on temperature

The InAs quantum well heterostructure was successfully grown on a semi-insulating GaAs substrate by MBE. On the GaAs substrate, the semi-insulating AlGaAsSb was grown to a thickness of 600 nm as the buffer layer, followed by a 15 nm InAs channel layer and a 35 nm AlGaAsSb doped layer together with 10 nm GaAsSb cap layer successively. The electron mobility and the sheet carrier concentration of the 15 nm InAs heterostructure was about 1 m² V⁻¹ s⁻¹ and 4.5×10¹² cm⁻², respectively, at room temperature. This heterostructure is equivalent to the heavily doped InAs substrate with little change of the electron mobility on temperature. This device has typical 1/f noise characteristics without any large bulge throughout the frequency and the temperature ranges observed. The Hooge parameter was α_H=1×10⁻³ at room temperature, decreasing monotonically with the decreasing temperature down to 5×10⁻⁴ at 50 K, indicating characteristics of the virtually constant mobility and constant carrier concentration device.