共查询到20条相似文献,搜索用时 15 毫秒
1.
In order to better understand the electrical and optical properties of GaAs and AlxGa1-x As used in making double heterojunction lasers, we have studied the Hall coefficient, resistivity and photoluminescence behavior
of doped epitaxial samples of these materials. In particular, we report results on Ge-doped GaAs and Alx Ga1-x As, Sn-doped AlxGa1-x As and Si-Te-doped GaAs single crystal layers which were grown on GaAs substrates by the liquid phase epitaxial method. The
effects of impurities in the solution on the carrier concentration, mobility, photoluminescence spectra and possible recombination
processes in these layers are discussed. 相似文献
2.
K. Yasuda K. Kojima K. Mori Y. Kubota T. Nimura F. Inukai Y. Asai 《Journal of Electronic Materials》1998,27(6):527-531
Electrical and photoluminescence properties of iodine doped CdZnTe (CZT) layers grown by metalorganic vapor phase epitaxy
have been studied. Doped layers showed an n-type conductivity from the Zn composition x=0 (CdTe) to 0.07. Above x=0.07, resistivities
of doped layers increased steeply up to 106 Ω-cm. Resistivities of doped CZT layers were higher than those of undoped layers above x=0.6. Photoluminescence intensity
of doped layers increased compared to undoped layers. Doped CdTe and ZnTe layers showed neutral donor bound exciton emission
lines at the exciton related region. Also, these layers showed an increase in emission intensity at the donor acceptor pair
recombination bands. Sharp emission lines were observed in doped CZT layers at around 1.49 eV. These emission lines were considered
to be originated from GaAs substrates which were optically excited by the intense emission from doped CZT layers. 相似文献
3.
Pascal F. Delannoy F. Bougnot J. Gouskov L. Bougnot G. Grosse P. Kaoukab J. 《Journal of Electronic Materials》1990,19(2):187-195
The growth of GaSb by MOVPE and itsn-type doping using a dimethyltellurium dopant source are investigated. The results of growth rate, morphology and Te incorporation
as a function of growth parameters are given. Increasing growth temperature and V/III reactant ratio were found to reduce
the Te incorporation. The lowest Hall carrier concentrations obtained at room-temperature, onp-type andn-type MOVPE GaSb are respectively:p
H= 2.2 × 1016cm−3 with a Hall mobility ofμ
H= 860 cm2/V.s andn
H= 8.5 × 1015cm−3 withμ
H= 3860 cm2/V.s. Furthermore, Hall mobilities as high as 5000 cm2/V.s were measured onn-type GaSb samples. 相似文献
4.
We examined the electrical and optical properties of vanadium-doped GaAs grown by metalorganic vapour phase epitaxy using vanadium tetrachloride (VCl4) as a novel dopant source. Samples with various vanadium incorporations were investigated. All samples were n type. The electron concentration dependence on the VCl4 flow rate was established. At 15 K, by comparison with undoped layers grown in the same conditions, photoluminescence spectra of V-doped exhibited three new emission bands: at 1.41, 1 and 0.72 eV. The 1 and 0.72 eV band emissions were attributed to V2+ and V3+ intracenter emission, while the 1.41 eV band was suggested to be a donor-bound transition. The identity of the donor is tentatively attributed to a donor complex that associates vanadium to an arsenic vacancy. From Hall effect as function of temperature, the donor ionisation energy was estimated to be about 102±5 meV. 相似文献
5.
D. B. Gladden W. D. Goodhue C. A. Wang G. A. Lincoln 《Journal of Electronic Materials》1992,21(1):109-114
Electrical and structural measurements have been performed on novel test structures incorporatingp-type GaAs epilayers grown by organometallic vapor phase atomic layer epitaxy on the vertical sidewalls of semi-insulating
GaAs rods formed by ion-beam-assisted etching. Preliminary results indicate that the vertical-sidewall epilayers have excellent
crystal quality and sufficient electrical quality to support a sidewall-epitaxy device technology. Some examples of candidate
electronic, electrooptic, and photonic devices for vertical-sidewall fabrication are FETs, resistors, waveguides, modulators,
and quantum-wire and quantum-dot lasers. 相似文献
6.
7.
Isotype heterojunctions of n-InAsSb/N-GaSb were grown by liquid phase epitaxy from Sb-solution. The current-voltage and capacitance-voltage
characteristics of these structures were investigated. Valence band and conduction band offsets were measured to be AEv =
0.40 eV and AEc = 0.84 eV, respectively, in good agreement with theory. Electroluminescence emission at 4 am from these isotype
heterojunction diodes is reported for the first time. The injection mechanisms determining luminescence efficiency are also
briefly discussed. 相似文献
8.
M. C. Hales 《Journal of Electronic Materials》1980,9(2):355-370
A detailed experimental study has been carried out to determine the limitations to growth in a horizontal chloride VPE reactor.
Growth rate has been examined as a function of input parameters such as temperature, flow rate and gas phase composition in
both the source and seed regions of the system. Although it is not possible in a simple system to make every one of these
six variables independent of every other, results indicate that source conditions play a significant part in limiting the
overall growth process. In general, for fastest growth rate the flow rate and mole fraction over the source should be high,
although for most efficient and reproducible growth low mole fraction and flow are more desirable. 相似文献
9.
B. C. Tousley S. M. Mehta A. I. Lobad P. J. Rodney P. M. Fauchet P. Cooke 《Journal of Electronic Materials》1993,22(12):1477-1480
A femtosecond, tunable color center laser was used to conduct degenerate pump-probe transmission spectroscopy of thin film
low temperature grown molecular beam epitaxy In0.53Ga0.47As samples. Low temperature molecular beam epitaxy In0.53Ga0.47As exhibits a growth-temperature dependent femtosecond optical response when probed near the conduction band edge. Below Tg=250°C, the optical response time of the material is subpicosecond in duration, and we observed induced absorption, which
we suggest is due to the formation of a quasi-“three-level system”. 相似文献
10.
Y. Nemirovsky S. Margalit E. Finkman Y. Shacham-Diamand I. Kidron 《Journal of Electronic Materials》1982,11(1):133-153
The growth of epitaxial layers of mercury-cadmium-telluride (Hg1-xCdxTe) with relatively low x (0.2-0.3) from Te-rich solutions in an open tube sliding system is studied. The development of a
semiclosed slider system with unique features permits the growth of low x material at atmospheric pressure. The quality of
the films is improved by the use of Cd1-yZyTe and Hg1-xCdxTe substrates instead of CdTe. The substrate effects and the growth procedure are discussed and a solidus line at a relatively
low temperature is reported. The asgrown epitaxial layers are p-type with hole concentration of the order of 1·1017 cm−3, hole mobility of about 300 cm2·V−1 sec−1 and excess minority carrier life-time of 3 nsec, at 77 K. 相似文献
11.
Electrical properties of low-temperature GaAs grown by molecular beam epitaxy and migration enhanced epitaxy 总被引:1,自引:0,他引:1
Measurements on low-temperature GaAs epitaxial layers (LT-GaAs) grown by molecular beam epitaxy and migration enhanced epitaxy
showed that the excess arsenic incorporated during growth played a crucial role in determining their electrical properties.
The electrical transport in LT-GaAs grown by a standard molecular beam epitaxy proceeded mainly via a hopping process, which
showed a higher activation energy and onset temperature than those usually observed in lightly doped semiconductors. Using
migration enhanced epitaxy to grow LT-GaAs, we were able to substantially reduce the density of As-rich defects and to achieve
a good Hall mobility in Be-doped LT-GaAs. The study presented here indicates that, with controlled excess arsenic incorporation
during growth, LT-GaAs can vary in a range of conduction properties and thus can be engineered for different device applications. 相似文献
12.
We report on the electrical characteristics of the two-dimensional electron gas (2DEG) formed in an InAlAs/InAsxP1-x/InP pseudomorphic composite-channel modulation-doped (MD) structure grown by solid source (arsenic and phosphorus) molecular
beam epitaxy (SSMBE). The As composition, x, of strained InAsxP1-x was determined by x-ray diffraction analysis of InP/InAsxP1-x/InP multi-quantum wells (MQWs) with compositions of x=0.14 to x=0.72. As the As composition increases, the room temperature
sheet resistance of InAlAs/InAsxP1-x/InP composite-channel MD structures grown over a range of As compositions decreased from 510 to 250 Ω/cm2, resulting from the greater 2DEG confinement and lower electron effective mass in the InAsxP1-x channel as x increases. The influence of growth conditions and epitaxial layer designs on the 2DEG mobility and concentration
were investigated using 300 K and 77 K Hall measurements. As the exposure time of the As4 flux on the growth front of InAsxP1-x increased during growth interruptions, the 2DEG mobility, in particular the 77K mobility, was considerably degraded due to
increased roughness at the InAlAs/InAsxP1-x interface. For the InAlAs/InAs0.6P0.4/InP composite-channel MD structure with a spacer thickness of 8 nm, the room temperature 2DEG mobility and density were 7200
cm2/Vs and 2.5 × 1012 cm−2, respectively. These results show the great potential of the InAlAs/InAsxP1-x/InP pseudomorphic composite-channel MD heterostructure for high frequency, power device applications. 相似文献
13.
N-type ZnSe with electron concentration up to 3 × 1020 cm−3 and low resistivity down to 1 × 10−4 ohm-cm, has been grown using a selective doping technique with chlorine during molecular beam epitaxy. The photoluminescence
evaluation shows that the selectively doped ZnSe layers are superior to uniformly doped ones, especially for the case of high-concentration
chlorine doping. The in-depth profile of chlorine concentration in a selectively doped sample was measured with secondary-ion
mass spectroscopy (SIMS). The SIMS analysis shows only slight diffusion of the incorporated chlorine atoms even in highly
doped samples. 相似文献
14.
用红外光荧光测量分析了Hg1-xCdxTe液相外延薄膜的发光特性,观察到局域激子及束缚激子发光.当外延层减薄至2μm后,PL信号的峰位将向高能方向移动,这是由于外延薄膜纵向组份不均匀引起的 相似文献
15.
Transparent and single crystalline indium-tin-oxide (ITO) nanowires (NWs) were grown by sputtering method. A thin Ni film of 5 nm was deposited before ITO sputtering. Thermal treatment forms Ni nanoparticles, which act as templates to diffuse Ni into the sputtered ITO layer to grow single crystalline ITO NWs. This Ni diffusion through an ITO NW was investigated by transmission electron microscope to observe the Ni-tip sitting on a single crystalline ITO NW. Meanwhile, a single crystalline ITO structure was found at bottom and body part of a single ITO NW without remaining of Ni atoms. This indicates the Ni atoms diffuse through the oxygen vacancies of ITO structure.Rapid thermal process (RTP) applied to generate an initial stage of a formation of Ni nanoparticles with variation in time periods to demonstrate the existence of an optimum condition to initiate ITO NW growth. Modulation in ITO sputtering condition was applied to verify the ITO NW growth or the ITO film growth. The Ni-assisted grown ITO layer has an improved electrical conductivity while maintaining a similar transmittance value to that of a single ITO layer. Electrically conductive and optically transparent ITO nanowire-coated surface morphology would provide a great opportunity for various photoelectric devices. 相似文献
16.
K. Doverspike L. B. Rowland D. K. Gaskill J. A. Freitas 《Journal of Electronic Materials》1995,24(4):269-273
This paper presents a comparative study of the properties of GaN grown by organometallic vapor phase epitaxy, using both a
GaN and A1N buffer layer, as a function of sapphire orientation (c-plane vs a-plane). Results are presented for varying the
thickness of the buffer layer, varying the growth temperature of the GaN film, and also varying the ammonia/trimethylgallium
mass flow ratio. The electron Hall mobilities of GaN films grown on an A1N buffer layer were, in general, higher compared
to films grown using a GaN buffer layer. In addition, growth on a-plane sapphire resulted in higher quality films (over a
wider range of buffer thicknesses) than growth on c-plane sapphire. The room temperature electron mobilities were also found
to be dependent on, not only the growth temperature, but also the ammonia/trimethylgallium mass flow ratio. 相似文献
17.
This work deals with the study by means of radioactive tracers and autoradiography, as well as measuring of galvanomagnetic
properties, of Ga and In doping of epitaxial CdxHg1−xTe layers during their crystallization from a Te-rich melt. Ga and In were introduced in the form of Ga72 and In114 master alloys with Te. The effective distribution coefficients of Ga and In during the crystallization of the CdxHg1−xTe solid solutions with x=0.20 to 0.23 were determined by cooling the Te-base melt to 515–470°C. Depending on the concentration
of the dopants and the time-temperature conditions of CdxHg1−xTe growth, these ratios for Ga and In were 1.5–2.0 and 1.0–1.5, respectively. The electrical activity of Ga and In was determined
after annealing of the CdxHg1−xTe layers in saturated Hg vapor at 270–300°C. In doping of the epitaxial layers to (3–8)×1014 cm−3 with subsequent annealing in saturated Hg vapor at ∼270°C increases the carrier lifetime approximately by a factor of two
as compared with the undoped material annealed under the same conditions. 相似文献
18.
Chinho Park Vladimir S. Ban Gregory H. Olsen Timothy J. Anderson Kenneth P. Quinlan 《Journal of Electronic Materials》1992,21(4):447-454
A novel, simplified hydride vapor phase epitaxy (VPE) method based on the utilization of Ga/In alloys as the group III source
was studied for deposition of GaxIn1-xAs. The effects of a wide range of experimental variables (i.e., inlet mole fractions of HC1 and AsH3, deposition temperature, gas velocity, Ga/ln alloy composition, and reactor geometry) on the ternary composition and growth
rate were investigated. The growth rate of Ga
x
In1−
xAs was found to increase with increasing deposition temperature and exhibited a maximum with inlet HC1 mole fraction. The
growth rate increases slightly with inlet AsH3 mole fraction and is independent of gas velocity. The Ga composition of the deposited film increased with increasing inlet
HC1 mole fraction and gas velocity. Increased In concentrations were observed with increases in inlet AsH3 mole fraction and deposition temperatures. Layers of Ga0.47In0.53As lattice matched to InP were successfully grown from alloys containing 5 to 8 at.% Ga. These layers were used to produce
state-of-the-artp- i- n photodetectors having the following characteristics: dark current,I
d(- 5 V) = 10-20 nA; responsivity,R = 0.84-0.86 A/W; capacitance,C = 0.88–0.92 pF; breakdown voltage,V
b
> 40 V. This study demonstrated for the first time that a simplified hydride VPE process with a Ga/ln alloy source is capable
of producing device quality epitaxial layers. 相似文献
19.