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21.
A. Y. Lew C. H. Yan R. B. Welstand J. T. Zhu C. W. Tu P. K. L. Yu E. T. Yu 《Journal of Electronic Materials》1997,26(2):64-69
We have used cross-sectional scanning tunneling microscopy (STM) to study interface structure in arsenide/phosphide heterostructures grown by gas-source molecular beam epitaxy (GSMBE) and by low-pressure metalorganic vapor phase epitaxy (LP-MOVPE). High-resolution images of GSMBE samples consisting of GaAs interrupted at 200Å intervals with a 40 s P2 flux reveal substantial, growth-temperature-dependent incorporation of phosphorus with nanometer-scale lateral variations in interface structure. STM images of InGaAs/InP multiple quantum well structures grown by LP-MOVPE show evidence of interface asymmetry and extensive atomic cross-incorporation at the interfaces. Data obtained by STM have been corroborated by high-resolution x-ray diffraction and reflection high-energy electron diffraction. Together, these studies provide direct information about nanometer-scale grading and lateral nonuniformity of arsenide/phosphide interfaces that can occur under these growth conditions. 相似文献
22.
B. K. Han L. Li M. J. Kappers R. F. Hicks H. Yoon M. S. Goorsky K. T. Higa 《Journal of Electronic Materials》1998,27(2):81-84
Thin films of InxGa1−xAs (0<x<0.012) on GaAs (001) were grown by metalorganic vapor phase epitaxy using triisopropylindium, triisobutylgallium,
and tertiarybutylarsine. The effect of the process conditions, temperature, and V/III ratio on the film quality was studied
using high resolution x-ray diffraction, scanning tunneling microscopy, and Hall measurements. High quality films were grown
at temperatures as low as 475 °C and at a V/III ratio of 100. However, under these conditions, a change in growth mode from
step flow to two-dimensional nucleation was observed. 相似文献
23.
H. Q. Hou W. G. Breiland B. E. Hammons R. M. Biefeld K. C. Baucom R. A. Stall 《Journal of Electronic Materials》1997,26(10):1178-1183
We present a comprehensive study on the growth of AlGaAs by using an alternative Al precursor, dimethylethylamine alane (DMEAA),
and a Ga coprecursor, either triethylgallium (TEG) or trimethylgallium (TMG). The growth rate of AlAs determined by using
in situ reflectometry was studied as a function of the growth temperature, V/III ratio, growth pressure, and rotation speed of the
substrate. The presence of gas phase reactions of DMEAA with arsine and TEG was indicated, and their reduction was achieved
at a lower growth pressure, lower V/III ratio, or a lower growth temperature. Negligible pre-reaction of DMEAA with TMG was
observed. Excellent material uniformity of AlGaAs was achieved on a 2″ diameter wafer. Secondary ion mass spectroscopy measurements
revealed extremely low C and O contents in the AlAs layer grown by DMEAA. Photoluminescence measurements suggested the presence
of some non-radiative defects in the as-grown DMEAA AlGaAs layers. 相似文献
24.
We investigated the possibility of forming a step-free quantum well structure. A step-free InAs monolayer was grown on a selectively
grown mesa by controlling surface phases with in-situ monitoring of surface photo-absorption. We selectively grew a GaAs buffer
at 800°C and cooled the sample keeping the (2×2)-like As stabilized surface. Atomic force microscopy (AFM) observation demonstrated
that fully step-free surfaces were formed on the 8 μm wide mesa. Then, a monolayer-thick InAs was formed on this step-free
surface and this InAs layer was capped by GaAs under the (2×2)-like condition. The quantum level of the step-free InAs layer
was evaluated by spatially resolved photoluminescence (μPL) measurement. Uniform PL intensity and the lack of a double layer
peak indicated the formation of a step-free InAs quantum well, which was in good agreement with AFM observation. 相似文献
25.
T. Yokogawa P. D. Floyd M. M. Hashemi J. L. Merz 《Journal of Electronic Materials》1994,23(2):101-104
We report the first confirmation of disordering of ZnSe/ZnS strained layer superlattices (SLSs) by Ge diffusion. The as-grown
sample showed ±first orders of well-resolved double crystal x-ray satellite peaks due to SLS periodic structure. However,
the satellite peaks completely disappeared in the Ge-diffused sample, indicating that the SLS structure was disordered by
the Ge diffusion. Photoluminescence measurements at 1.4K of both the as-grown and the annealed samples without Ge diffusion
show identical, sharp excitonic emission around 420 nm. After Ge diffusion, the PL peaks shift to higher energy confirming
the layer disordering of the SLS. 相似文献
26.
We grew a 1.3 μm strained-layer quantum well (SL-QW) laser with InGaP cladding layers on a lattice-relaxation buffer layer
by metalorganic vapor phase epitaxy. For the lattice-relaxation buffer, we used a compositionally graded InGaAs/GaAs structure.
The significantly reduced surface roughness of the InGaP cladding layers achieved by supplying a large amount of H2Se enables CW operation of our 1.3 μm SL-QW laser. We achieved a low threshold current of less than 10 mA and a high characteristic
temperature of 100K around room temperature. 相似文献
27.
V. Natarajan N. R. Taskar I. B. Bhat S. K. Ghandhi 《Journal of Electronic Materials》1988,17(6):479-483
The organometallic vapor phase epitaxy of HgCdTe onto (100)2°-(110) GaAs substrates is described in this paper. A buffer layer
of CdTe has been grown prior to the growth of HgCdTe, to take up the large lattice mismatch with the GaAs. Considerations
for the thickness of this buffer layer are outlined, and it is shown by quantitative Secondary Ion Mass Spectroscopy that
there is negligible diffusion of gallium from the GaAs substrate for the growth conditions described. Hall effect measurements
give mobilities comparable to those reported for bulk grown crystals. An extrinsicn-type carrier concentration of 2 × 1016/cm3 is obtained, and is mainly due to residual impurities in the starting chemicals. The alloy composition has been determined
at 298 K by Fourier transform infrared transmission (FTIR) spectrometry; this is found to be extremely uniform over a 15 ×
7 mm area, as evidenced by an overlapping of FTIR plots taken over this area. HgCdTe layers have been grown on buffer layers
varying in thickness from 0.1 to 1.9μm. It is found that a buffer thickness of about 1.9μm or larger is required to obtain high quality HgCdTe, both in terms of the electrical characteristics (mobility and carrier
concentration) and the infrared transmission curves (peak transmission). 相似文献
28.
29.
N. Carr J. Thompson G. G. Jones I. Griffith A. J. Moseley P. M. Charles 《Journal of Electronic Materials》1995,24(11):1617-1620
The use of optoelectronic integrated circuits (OEICs) is now emerging as a practical technology for a variety of applications, particularly in advanced telecommunications. OEICs consist of a range of devices such as lasers, waveguides, modulators, amplifiers, transistors, detectors, etc. fabricated on the same substrate. When a semi-insulating substrate is used, these devices can be electrically isolated by channel etching, resulting in a low capacitance structure with reduced electrical interference between the subcomponents. One of the devices which is particularly advantageous for this type of integration scheme is the distributed feedback (DFB) laser. The laser can be made to function more efficiently by minimizing the current flowing outside the active region. This can be achieved by surrounding the active region with semi-insulating iron doped InP. This work describes for the first time, the MOVPE growth, fabrication, and device characterization of 1.3 um buried heterostructure DFB MQW lasers, which combine the advantages of using both a semi-insulating substrate and a semi-insulating infill region in the same device structure. The potential advantage of this design scheme is improved OEIC performance as a result of, reduced capacitance and electrical crosstalk, enhanced laser output power, higher speed, increased efficiency, wider operating temperature and reduced threshold current. The laser active region consists of 8 x 140 Å quantum wells of GalnAsP (λ = 1.3 μm) and 110 Åbarriers of GalnAsP (λ= 1.07 μm). Single mode 1.3 urn devices of length 250 μm operating at room temperature produced threshold currents of 8 mA, efficiencies of up to 25%, output powers of 18 mW at 80 mA (pulsed), and a frequency response greater than 12GHz. The parasitic capacitance was estimated to be less than 3 pF. 相似文献
30.
A. Mircea R. Azoulay L. Dugrand R. Mellet K. Rao M. Sacilotti 《Journal of Electronic Materials》1984,13(3):603-620
We present a procedure for the MOVPE of InP as simple as the one currently used for GaAs. InP and InGaAsP alloys are grown
on InP substrates using trimethy1indium (TMI), phosphine, trimethylgallium (TMG) and arsine. The choice of carrier gas is
important ; a mixture of hydrogen and nitrogen allowed us to grow uniform layers over large areas at atmospheric pressure,
without pyrolizing the phosphine or separating the input reactants. Preliminary characterization results are presented.
Most information contained in this paper was presented at the 1983 Electron Materials Conference as paper Cl. 相似文献