共查询到20条相似文献,搜索用时 31 毫秒
1.
M. Peter J. Forker K. Winkler K. H. Bachem J. Wagner 《Journal of Electronic Materials》1995,24(11):1551-1555
Two types of quantum well (QW) structures grown lattice matched on (100) GaAs have been studied. The first type of structure
consists of pseudomorphic GaAsxSb1-x/GaAs (x≤0.3) SQWs which show emission wavelengths longer than those reported for pseudomorphic InyGa1−yAs/GaAs QWs. However, the attractive emission wavelength of 1.3 μm has not been achieved. To reach this goal, a novel type
of bilayer QW (BQW) has been grown consisting of a stack of two adjacent pseudomorphic layers of GaAsxSb1−x and In Ga1-y As embedded between GaAs confinement layers. In this BQW, a type-II heterojunction is formed between GaAsxSb1−x and InyGa1−yAs, resulting in a spatially indirect radiative recombination of electrons and holes at emission wavelengths longer than those
achieved in the GaAsxSb1−x/GaAs and IiyGa1−yAs/GaAs SQWs. The longest 300K emission wavelength observed so far was 1.332 μm. 相似文献
2.
The effective band gap energy of InxGa1−xAs/GaAs strained quantum wells (QWs) is investigated by photoluminescence spectroscopy (PL) in the range 12–295 K. The temperature
dependence of the band gap energy of strained QWs correlates well with that of bulk InxGa1−xAs of similar composition. Deviations from the band gap variation of bulk material at low temperatures (12–90 K) are interpreted
in terms of exciton localization. The differences ΔE(12 K) between the measured PL peak energies and the expected transition
energies at 12 K (obtained by simulating the measured temperature dependence of the PL peak positions by the well-known Varshni
relation) are suggested to be closely related to the Stokes shifts that often exist between PL and PL excitation spectra of
QWs. A linear relation is found between the PL full-width at half-maximum measured at 12 K and ΔE for a range of QWs prepared
under different growth conditions. Excitonic recombination is inferred to be dominant in the PL transitions at the highest
temperatures investigated—even at room temperature. 相似文献
3.
Takahiro Kitada Tatsuya Saeki Masanobu Ohashi Satoshi Shimomura Akira Adachi Yasunori Okamoto Naokatsu Sano Satoshi Hiyamizu 《Journal of Electronic Materials》1998,27(9):1043-1046
Effectively atomically flat interfaces over a macroscopic area (“(411)A super-flat interfaces”) were successfully achieved
in In0.53Ga0.47As/In0.52Al0.48As quantum wells (QWs) grown on (411)A InP substrates by molecular beam epitaxy (MBE) at a substrate temperature of 570°C
and V/III=6. Surface morphology of the In0.53Ga0.47As/In0.52Al0.48As QWs was smooth and featureless, while a rough surface of those simultaneously grown on a (100) InP substrate was observed.
Photoluminescence (PL) linewidths at 4.2 K from the (411)A QWs with well width of 0.6–12 nm were 20–30 % narrower than those
grown on a (100) InP substrate and also they are almost as narrow as each of split PL peaks for those of growth-interrupted
QWs on a (100) InP substrate. In the case of the (411)A QWs, only one PL peak with very narrow linewidth was observed from
each QW over a large distance (7 mm) on a wafer. 相似文献
4.
M.A. Abid H. Abu Hassan Z. Hassan S.S. Ng S.K. Mohd Bakhori N.H.Abd. Raof 《Materials Science in Semiconductor Processing》2011,14(2):164-169
High-resolution X-ray diffraction (HR-XRD) with rocking curve, atomic force microscopy (AFM) and photoluminescence (PL) spectroscopy have been performed on high-quality quaternary AlxInyGa1−x−yN thin films at room temperature. The AlxInyGa1−x−yN films were grown on c-plane (0 0 0 1) sapphire substrates with AlN as buffer layers using a molecular beam epitaxy (MBE) technique with aluminum (Al) mole fractions x ranging from 0.0 to 0.2 and constant indium (In) mole fraction y=0.1. HR-XRD measurements confirmed the high crystalline quality of these alloys without any phase separation. The X-ray rocking curve of AlxInyGa1−x−yN films typically shows full widths at half maximum (FWHM) intensity between 14.4 and 28.8 arcmin. AFM measurements revealed a two-dimensional (2D) growth mode with a smooth surface morphology of quaternary epilayers. PL spectra exhibited both an enhancement of the integrated intensity and an increasing blueshift with increased Al content with reference to the ternary sample In0.1Ga0.90N. Both effects arise from Al-enhanced exciton localization. PL was used to determine the behavior of the energy band gap of the quaternary films, which was found to increase with increasing Al composition from 0.05 to 0.2. This trend is expected since the incorporation of Al increases the energy band gap of ternary In0.1Ga0.90N (3.004 eV). We have also investigated the bowing parameter for the variation of energy band gaps and found it to be very sensitive on the Al composition. A value of b=10.4 has been obtained for our quaternary AlxInyGa1−x−yN alloys. 相似文献
5.
J. S. Major L. J. Guido N. Holonyak K. C. Hsieh E. J. Vesely D. W. Nam D. C. Hall J. E. Baker P. Gavrilovic K. Meehan W. Stutius J. E. Williams 《Journal of Electronic Materials》1990,19(1):59-66
In these experiments impurity-induced layer disordering (IILD) utilizing chemical reduction of SiO2 by Al (from Al0.8Ga0.2As) is employed to generate Si and O to effect layer disordering. The SiO2-Al0.8Ga0.2As reaction is studied with respect to annealing ambient. By controlling the extent of disordering via As4 overpressure, closely spaced (∼1μm) Si-O IILD buried heterostructure lasers can be optically coupled or uncoupled. Direct observation of O incorporation into
the buried layers is shown using secondary ion mass spectroscopy (SIMS). The thermal stability of separate-confinement AlyGa1−yAs-GaAs-InxGa1−xAs quantum well heterostructure (QWH) laser crystals is investigated using SIMS, transmission electron microscopy (TEM), and
photoluminescence (PL) measurements. The data show that the thermal stability of a strained-layer In0.1Ga0.9As quantum well (QW) is strongly dependent upon: (1) the layer thickness and heterointerfaces of the AlyGa1−yAs-GaAs waveguide layers located directly above and below the QW, (2) the type of surface encapsulant employed, and (3) the
annealing ambient. Narrow single-stripe (<2μm) lasers fabricated via Si-O diffusion and layer disordering exhibit low threshold currents (Ith ∼ 4 mA) and differential quantum efficiencies,η, of 22% per facet under continuous (cw) room-temperature operation. 相似文献
6.
J. P. Estrera W. M. Duncan Y. C. Kao H. Y. Liu E. A. Beam 《Journal of Electronic Materials》1991,20(12):983-987
We present a systematic study of In
x
Ga1−x
As on InP grown by molecular beam epitaxy using the characterization techniques of Fourier transform photoluminescence, x-ray
diffraction, micro-Raman spectroscopy, and photoreflectance spectroscopy. The four techniques were used to determine and correlate
the fundamental parameters of band-gap energy, phonon frequency and composition. Comparing room temperature (293 K) PL and
low temperature PL indicate the presence of a partially ionized acceptor with binding energy of about 13 meV in the unintentionally
doped material. Double crystal x-ray diffraction (XRD) using a symmetric <400> and asymmetric <224> reflections was also employed.
The use of two reflections gives precise lattice constants, composition, and extent of film relaxation. Micro-Raman spectroscopy
was used to measure phonon frequencies in the In
x
Ga1−x
As films and correlated to XRD composition. Room temperature photoreflectance (PR) was used to determine band-gap energy for
both the low and intermediate field cases. Band gap energies determined at room temperature by PL and PR were in agreement
within experimental error. 相似文献
7.
Long-wavelength photodiodes based on Ga1−x
InxAsySb1−y
wit composition near the miscibility boundary
The possibility of using liquid-phase epitaxy to obtain Ga1−x
InxAsySb1−y
solid solutions isoperiodic with GaSb near the miscibility boundary is investigated. The effect of crystallographic orientation
of the substrate on the composition of the solid solutions grown in this way is examined, and the indium concentration is
observed to grow from 0.215 to 0.238 in the Ga1−x
InxAsySb1−y
solid phase in the series of substrate orientations (100), (111)A, (111)B. A change in the composition of the solid solution
leads to a shift of the long-wavelength edge of the spectral distribution of the photosensitivity. The use of a GaSb (111)B
substrate made it possible, without lowering the epitaxy temperature, to increase the indium content in the solid phase to
23.8% and to create long-wavelength photodiodes with spectral photosensitivity threshold λ
th=2.55 μm. The primary characteristics of such photodiodes are described, along with aspects of their fabrication. The proposed
fabrication technique shows potential for building optoelectronic devices (lasers, LED’s, photodiodes) based on Ga1−x
InxAsySb1−y
solid solutions with red boundary as high as 2.7 μm.
Fiz. Tekh. Poluprovodn. 33, 249–253 (February 1999) 相似文献
8.
D. A. Vinokurov V. A. Kapitonov D. N. Nikolaev Z. N. Sokolova A. L. Stankevich V. V. Shamakhov I. S. Tarasov 《Semiconductors》2009,43(10):1334-1337
Results of photoluminescence (PL) studies of heterostructures with strongly strained InxGa1 ? x As quantum wells (QWs) are presented. It is shown that the dependence of the PL intensity on the QW thickness has a maximum whose position depends on the composition of the In x Ga1 ? x As solid solution. The PL wavelength at the maximum intensity is 1.13 µm at a QW thickness of 60 µm at a QW thickness of 50 Å for x = 0.39 and 0.42, respectively. 相似文献
9.
Based on intrinsic alloy phase formation chemistry and thermodynamics, a novel and unique way of producing compositionally
homogeneous multi-component (binary, ternary, quaternary) semiconductor materials is presented. A free energy minimization
computer program licensed from AEA Technology Engineering Software, Inc., has been employed to study the composition of the
solidifying phases from Ga-In-As-Sb melts at different temperatures and with various liquid compositions. The solid phases
have been identified (theoretically and experimentally) to be either ternary compounds of Ga1−xInxAsySb1−y depending on the melt temperature and composition. By engineering the thermochemistry of preferential phase formation in
the Ga-In-As-Sb melt, compositionally uniform, single phase, crack free, large polycrystalline Ga1−xInxSb and Ga1−xInxAs have been grown. 相似文献
10.
E. N. Vigdorovich 《Semiconductors》2011,45(13):1642-1645
Some properties of the In1 − y
Ga
y
As1 − x
N
x
unordered alloys and physical prerequisites of their use in science and technology are considered. The results of studying
the intermolecular interaction in the systems under study and the features of their application to the In1 − y
Ga
y
As1 − x
N
x
/GaAs functional hetero-structures are presented. 相似文献
11.
Guan-Ru Chen Hao-Hsiung Lin Jyh-Shyang Wang Ding-Kang Shih 《Journal of Electronic Materials》2003,32(4):244-248
Optical properties of InAs1−xNx/In0.53Ga0.47As (hereafter, abbreviated as InAsN/InGaAs) single quantum wells (SQWs) grown on InP substrates by gas source molecular-beam
epitaxy are studied using photoluminescence (PL) measurements. By comparing the low-temperature PL spectra of InAs/InGaAs
and InAsN/InGaAs SQWs, InAs and InAsN phases are found to coexist in the InAsN layer. Such serious alloy inhomogeneities result
in obvious exciton localization by potential irregularities. The blue shift of the PL peak after rapid thermal annealing (RTA)
is found to originate mainly from As-N interdiffusion inside the well layer. According to the temperature-dependent PL results,
uniformity of the InAsN layer can be effectively improved by RTA, and the exciton localization is, thus, relieved. Comparison
of luminescence quenching and excitation-power-dependent PL behavior between the QWs with and without nitrogen content suggests
that the quality of the QW is degraded by the introduction of nitrogen, and the degradation can only be partially recovered
by post-growth RTA. 相似文献
12.
Band-edge photoluminescence spectra of heavily donor-doped samples of InxGa1−x
As1−y
Py (x=0.77, y=0.53) were investigated in the temperature range (77–300) K. A theory of luminescence that takes into account fluctuations
in the band-edge potentials due to nonuniform distribution of impurities is used to calculate temperature dependences of the
positions and half-widths of peaks in these spectra. Good agreement is obtained between experimental and calculated curves.
For heavily doped InxGa1−x
As1−y
Py samples with either p-or n-type conductivity, the peak energy of the band-edge PL is observed to shift towards lower frequencies at low temperatures.
This shift is accompanied by broadening of the spectra and a decrease in the photoluminescence intensity compared to the analogous
parameters for the spectra of undoped material. Possible mechanisms for radiative recombination are analyzed.
Fiz. Tekh. Poluprovodn. 33, 907–912 (August 1999) 相似文献
13.
The effect of substrate misorientation on phase separation in Ga1−xInxAsySb1−y nominally lattice matched to GaSb is reported. The layers were grown at 575°C by organometallic vapor phase epitaxy on vicinal
(001) GaSb substrates, miscut
or (101). Ga1−xInxAsySb1−y (x ~ 0.1, ~ 0.09) layers, which have 300-K photoluminescence (PL) peak emission at ~2.1 μm, grow stepbunched and exhibit
minimal phase separation. The full width at half maximum of 4-K PL spectra is slightly smaller at 7 meV for layers grown on
substrates miscut toward
compared to 9 meV for layers grown on substrates miscut toward
and (101). Ga1−xInxAsySb1−y layers with higher alloy composition (0.16≤x≤0.19, 0.14≤y≤0.17), which have 300-K PL peak emission at ~2.4 μm, have significant
phase separation. These layers are characterized by increased lattice constant variations and epitaxial tilt, broad PL spectra
with significant band tailing, and strong contrast modulation in transmission electron microscopy. The degree of decomposition
depends on substrate miscut direction: Ga1−xInxAsySb1−y layers grown on (001)
substrates are more homogeneous than those grown on (001)
and (001)2°→(101) substrates. The results are attributed to the smaller adatom diffusion length on substrates miscut toward
. 相似文献
14.
V. I. Vasil’ev D. Akhmedov A. G. Geryagin V. I. Kuchinskii I. P. Nikitina V. M. Smirnov D. N. Tret’yakov 《Semiconductors》1999,33(9):1034-1036
Nearly isoperiodic solitary Ga1−x
InxAsySb1−y
/GaSb heterostructures, in which the composition of the solid solution should be found inside the region of spinodal decay
(x⩽0.4), were grown by liquid-phase epitaxy from solution-melts enriched with antimony. On the basis of the results of a study
of structural and luminescence properties of Ga1−x
InxAsySb1−y
/GaSb heterostructures we have determined the main conditions ensuring reproducible growth of epitaxial layers, homogeneous
in the composition of their solid solutions in the region where the existence of processes of spinodal and binodal decay have
been theoretically predicted. It is shown that the magnitude and sign of the deformation which the layer undergoes during
growth and also the thickness of the layer are the main factors influencing the properties of the growing GaInAsSb solid solutions
in the spinodal-decay zone.
Fiz. Tekh. Poluprovodn. 33, 1134–1136 (September 1999) 相似文献
15.
S. V. Evstigneev R. M. Imamov A. A. Lomov Yu. G. Sadof’ev Yu. V. Khabarov M. A. Chuev D. S. Shipitsin 《Semiconductors》2000,34(6):693-699
The structures grown by molecular-beam epitaxy with InxGa1?x As quantum wells (QWs) in GaAs were studied by X-ray diffractometry and low-temperature photoluminescence techniques. The inhomogeneity of the QW composition along the growth direction was established. Energy positions of the exciton recombination lines in the QWs with step-graded In distribution were calculated, and good agreement with the experimental data was obtained. 相似文献
16.
We have investigated the growth of quaternary In1−xGaxAsyP1−y/InP materials using TBA and TBP in a N2 ambient. This process improves significantly the uniformity of In1−xGaxAs/InP QWs whereas it does not improve the quaternary Q(1.3)/InP uniformity compared to the conventional process utilizing
AsH3 and PH3 in H2. The effect on the x and y uniformity for different combinations of the group-V precursors TBA, TBP, PH3, and AsH3 with the carrier gases H2 and N2 is evaluated. Advantages with the TBA/TBP/N2 process are discussed. 相似文献
17.
Chihiro J. Uchibori Masayuki Okunishi T. Oku A. Otsuki Naoki Ono Masanori Murakami 《Journal of Electronic Materials》1994,23(9):983-989
The formation mechanisms of InAs/Ni/W ohmic contacts to n-type GaAs prepared by radio-frequency (rf) sputtering were studied
by measuring contact resistances (Rc) using a transmission line method and by analyzing the interfacial structure mainly by x-ray diffraction and transmission
electron microscopy. Current-voltage characteristics of the InAs/Ni/W contacts after annealing at temperatures above 600°C
showed “ohmic-like behavior.” In order to obtain the “ohmic” behavior in the contacts, pre-heating at 300°C prior to high
temperature annealing was found to be essential. The contacts showed ohmic behavior after annealing at temperatures in the
range of 500∼850°C and contact resistance values of as low as ∼0.3Ω-mm were obtained. By analyzing the interfacial structures
of these contacts, InxGa1−xAs layers with low density of misfit dislocations at the InxGa1−xAs and GaAs interface were observed to grow epitaxially on the GaAs substrate upon heating at high temperatures. This intermediate
InxGa1−xAs layer is believed to divide the high energy barrier at the contact metal and GaAs interface into two low barriers, resulting
in reduction of the contact resistance. In addition, Ni was found to play a key role to relax a strain in the InxGa1−xAs layer (introduced due to lattice mismatch between the InxGa1−xAs and GaAs) by forming an intermediate NixGaAs layer on the GaAs surface prior to formation of the InxGa1−xxAs layer. 相似文献
18.
D. Garbuzov D. -S. Kim S. R. Forrest R. Menna M. Lange G. H. Olsen M. Cohen 《Journal of Electronic Materials》1996,25(9):1501-1505
Photoluminescence spectra and efficiency have been measured for several strained InAsyP1−yInxGa1−xAs (0.28 < y ≤ 0.62; 0.66 ≤ x ≤ 0.83) double heterostructures grown by vapor phase epitaxy on InP substrates with graded InAsP
buffer layers. Luminescence peak positions between the wavelengths of 1.99 and 2.57 (μm at a temperature of 295K are consistent
with bandgap luminescence from the InxGa1−xAs active regions. Despite a high density of dislocations in the buffer layers, internal radiative recombination efficiencies
of from 25 to 50% for the structures are found at 295K. 相似文献
19.
The optical properties of ZnO/Mg
x
Zn1−x
O (x = 0.17) quantum wells (QWs) grown on c-plane sapphire substrates by pulsed laser deposition are presented. A blueshift in the low-temperature photoluminescence
(PL) of the QWs illustrates quantum confinement effects as a function of ZnO well widths in the range from 3 nm to 10 nm.
Enhanced luminescence properties are observed with increasing quantum confinement. PL data indicate weak polarization effects
associated with the heterojunctions. Temperature-dependent PL measurements indicate carrier/exciton localization with activation
energy of approximately 4−5 meV, which are attributed to potential fluctuations at the well-barrier interface. 相似文献
20.
Based on our kinetics models for gas source molecular beam epitaxy of mixed group-V ternary materials, the group-V composition
control in InyGa1−yAs1−xPx epilayers has been studied. The P or As composition in InyGa1−yAs1−xPx (lattice matched to InP or GaAs) can be obtained from a simple equation for substrate temperatures below 500°C. This has
been verified by a series of experimental results. 相似文献