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排序方式: 共有239条查询结果,搜索用时 0 毫秒
1.
GaN的MOVPE生长和m-i-n型蓝光LED的试制 总被引:1,自引:0,他引:1
利用自行研制的常压MOVPE设备和全部国产MO源,采用低温生长缓冲层技术,在蓝宝石(α-Al2O3)衬底上获得了高质量的GaN外延层。未掺杂的GaN外延层的室温电子迁移率已达114cm2/V.s,载流于浓度为2×1018。77K光致发光谱近带边发射峰波长为365nm,其线宽为4DmeV。X射线双晶衍射回摆曲线的线宽为360arcsec。用Zn掺杂生长了绝缘的i-GaN层。在此基础上研制了m-i-n型GaN的LED,并在室温正向偏压下发出波长为455nm的蓝光。 相似文献
2.
J. W. Huang J. M. Ryan K. L. Bray T. F. Kuech 《Journal of Electronic Materials》1995,24(11):1539-1546
The defect engineering in metalorganic vapor phase epitaxy InxGa1-xAs and InP by controlled oxygen doping using diethyl aluminum ethoxide (DEALO) was developed in this study. DEALO doping has
led to the incorporation of Al and O, and the compensation of shallow Si donors in InxGa1−xAs: Si with 0 ≤ x ≤ 0.25. With the same DEALO mole fraction during growth, the incorporation of Al and O was found to be independent
of x, but the compensation of Si donors decreases with increasing In content. Deep level transient spectroscopy analysis on
a series of InxGa1-xAs: Si. samples with 0 ≤ x ≤ 0.18 revealed that oxygen incorporation led to a set of deep levels, similar to those found in
DEALO doped GaAs. As the In composition was increased, one or more of these deep levels became resonant with the conduction
band and led to a high electron concentration in oxygen doped In0.53Ga0.47As. Low temperature photoluminescence emission measurements at 12K on the same set of samples revealed the quenching of the
near-band edge peak, and the appearance of new oxygen-induced emission features. DEALO doping in InP has also led to the incorporation
of Al and O, and the compensation of Si donors due to oxygen-induced multiple deep levels. 相似文献
3.
The growth of nominally undoped GaSb layers by atmospheric pressure metalorganic vapor phase epitaxy on GaSb and GaAs substrates
is studied. Trimethylgallium and trimethylantimony are used as precursors for the growth at 600°C in a horizontal reactor.
The effect of carrier gas flow, V/III-ratio, and trimethylgallium partial pressure on surface morphology, electrical properties
and photoluminescence is investigated. The optimum values for the growth parameters are established. The carrier gas flow
is shown to have a significant effect on the surface morphology. The optimum growth rate is found to be 3–8 μm/ h, which is
higher than previously reported. The 2.5 μm thick GaSb layers on GaAs are p-type, having at optimized growth conditions room-temperature
hole mobility and hole concentration of 800 cm2 V−1 s−1 and 3·1016 cm-3, respectively. The homoepitaxial GaSb layer grown with the same parameters has mirror-like surface and the photoluminescence
spectrum is dominated by strong excitonic lines. 相似文献
4.
P. Kurpas A. Oster M. Weyers A. Rumberg K. Knorr W. Richter 《Journal of Electronic Materials》1997,26(10):1159-1163
Reflectance anisotropy spectroscopy (RAS) has been used to study As-by-P exchange during metalorganic vapor phase epitaxy.
The study focuses on the processes occurring during switching from GaAs to GaInP, especially the effect of purging PH3 over a GaAs surface. GaAsP/GaAs superlattices of different periodicity were grown and the P-content was determined by high-resolution
x-ray diffraction and correlated to the RAS spectra. From the temperature dependence of the P-content, an activation energy
of 0.56 eV was estimated for the incorporation mechanism. In addition to the insights into the processes at mixed group-V
heterointerfaces, our study demonstrates the reproducibility of RAS transients that thus can be used for process monitoring. 相似文献
5.
K. Yasuda Y. Tomita Y. Masuda T. Ishiguro Y. Kawauchi H. Morishita Y. Agata 《Journal of Electronic Materials》2002,31(7):785-790
Iodine doping of CdTe layers grown on (100) GaAs by metal-organic vapor phase epitaxy (MOVPE) was studied using diethyltelluride
(DETe) and diisopropyltelluride (DiPTe) as tellurium precursors and ethyliodine (EI) as a dopant. Electron densities of doped
layers increased gradually with decreasing the growth temperature from 425°C to 325°C. Doped layers grown with DETe had higher
electron densities than those grown with DiPTe. When the hot-wall temperature was increased from 200°C to 250°C at the growth
temperature of 325°C, doped layers grown with DETe showed an increase of the electron density from 3.7×1016 cm−3 to 2.6×1018 cm−3. On the other hand, such an increase of the electron density was not observed for layers grown with DiPTe. The mechanisms
for different doping properties for DETe and DiPTe were studied on the basis of the growth characteristics for these precursors.
Higher thermal stability of DETe than that of DiPTe was considered to cause the difference of doping properties. With increasing
the hot-wall temperature from 200°C to 250°C, the effective ratio of Cd to Te species on the growth surface became larger
for layers grown with DETe than those grown with DiPTe. This was considered to decrease the compensation of doped iodine and
to increase the electron density of layers grown with DETe. The effective ratio of Cd to Te species on the growth surface
also increased with decreasing growth temperature. This was considered to increase the electron density with decreasing growth
temperature. 相似文献
6.
G. Coudenys I. Moeeman G. Vermeire F. Vermaerke Y. Zhu P. Van Daele P. Demeester E. Maayan B. Elsner J. Salzman E. Finkman 《Journal of Electronic Materials》1994,23(2):225-232
The shadow masked growth technique is presented as a tool to achieve thickness and bandgap variations laterally over the substrate
during metalorganic vapor phase epitaxy. Lateral thickness and bandgap variations are very important for the fabrication of
photonic integrated circuits, where several passive and active optical components need to be integrated on the same substrate.
Several aspects of the shadow masked growth are characterized for InP based materials as well as for GaAs based materials.
Thickness reductions are studied as a function of the mask dimensions, the reactor pressure, the orientation of the masked
channels and the undercutting of the mask. The thickness reduction is strongly influenced by the mask dimensions and the reactor
pressure, while the influence of the orientation of the channels and the amount of undercutting is only significant for narrow
mask windows. During shadow masked growth, there are not only thickness variations but also compositional variations. Therefore,
we studied the changes in In/Ga and As/P ratios for InGaAs and InGaAsP layers. It appears that mainly the In/Ga-ratio is responsible
for compositional changes and that the As/P-ratio remains unchanged during shadow masked growth. 相似文献
7.
S. J. C. Irvine A. Stafford M. U. Ahmed A. Brown H. Kheyrandish 《Journal of Electronic Materials》1997,26(6):723-727
The first detailed comparison has been made of the metalorganic vapor phase epitaxy growth rates of CdTe, ZnTe, and ZnSe,
measured in situ with laser reflectometry. The comparison also includes the photo-assisted growth with visible radiation from
an argon ion laser. Using a standard Group II precursor (DMCd or DMZn.TEN) partial pressure of 1.5 × 10−4 atm, VI/II ratio of 1 and DIPM (M = Te, Se) the maximum growth rates are in the region of 10 to 15 AU/ s. Decrease in growth
rates of ZnTe at higher temperatures or higher laser powers have been attributed to the desorption from the substrate of unreacted
Te precursor. The behavior of DTBSe is quite different from DIPSe for both pyrolytic and photo-assisted growth. The maximum
growth rate is around 1 AU/ s with very little photo-enhancement, except at 300°C. Secondary ion mass spectroscopy analysis
of hydrogen concentration in the ZnSe layers shows high concentrations, up to 5.9 × 1019 atoms cm−3 for DTBSe grown ZnSe under pyrolytic conditions. These results show that the growth kinetics play an important part in the
incorporation of hydrogen and passivation of acceptor doped material. 相似文献
8.
Tuomas Haggren Ali Shah Anton Autere Joona-Pekko Kakko Veer Dhaka Maria Kim Teppo Huhtio Zhipei Sun Harri Lipsanen 《Nano Research》2017,10(8):2657-2666
Light management and electrical isolation are essential for the majority of optoelectronic nanowire (NW) devices.Here,we present a cost-effective technique,based on vapor-phase deposition of parylene-C and subsequent annealing,that provides conformal encapsulation,anti-reflective coating,improved optical properties,and electrical insulation for GaAs nanowires.The process presented allows facile encapsulation and insulation that is suitable for any nanowire structure.In particular,the parylene-C encapsulation functions as an efficient antireflection coating for the nanowires,with reflectivity down to <1% in the visible spectrum.Furthermore,the parylene-C coating increases photoluminescence intensity,suggesting improved light guiding to the NWs.Finally,based on this process,a NW LED was fabricated,which showed good diode performance and a clear electroluminescence signal.We believe the process can expand the fabrication possibilities and improve the performance of optoelectronic nanowire devices. 相似文献
9.
Wilson De Carvalho Jr. Mario Tosi Furtado Aryton André Bernussi Angelo Luiz Gobbi Mônica Alonso Cotta 《Journal of Electronic Materials》2000,29(1):62-68
We investigated the influence of the growth rate on the quality of zero-net-strained InGaAsP/InGaAsP/InP multiquantum well
structures for 1.55 μm emission grown by low pressure metalorganic vapor phase epitaxy. The samples consisted of fixed compressive
strained wells (ɛ=+1%) and tensile strained barriers (ɛ=−0.5%) grown with different quaternary bandgap wavelengths (λB=1.1–1.4 μm). Using higher growth rates, we obtained for the first time high quality zero net strained multi quantum well
structures, regardless having constant group V composition in the well and barriers. The samples were analyzed by x-ray diffraction,
photoluminescence and atomic force microscopy techniques. The amplitude of surface modulation roughness along [011] direction
decreased from 20 nm to 0.53 nm with increasing growth rate and/or quaternary compositions grown outside the miscibility gap.
A new deep PL broad emission band strongly correlated with the onset of wavy layer growth is also reported. Broad area and
ridge waveguide lasers with 10 wells exhibited low losses (34 cm−1) and low threshold current densities at infinite cavity length (1020 A·cm−2 and 1190 A·cm−2, respectively). 相似文献
10.
Koh Matsumoto Kazutada Ikenaga Jun Yamamoto Kazuki Naito Yoshiki Yano Akinori Ubukata Hiroki Tokunaga Tadanobu Arimura Katsuaki Cho Toshiya Tabuchi Akira Yamaguchi Yasuhiro Harada Yuzaburo Ban Kousuke Uchiyama 《半导体学报》2011,32(1):21-23
Growth rate has a direct impact on the productivity of nitride LED production.Atmospheric pressure growth of GaN with a growth rate as high as 10μm/h and also Al0.1Ga0.9N growth of 1μm/h by using 4 inch by 11 production scale MOVPE are described.XRD of(002) and(102) direction was 200 arcsec and 250 arcsec, respectively.Impact of the growth rate on productivity is discussed. 相似文献