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81.
A. N. Danilewsky S. Lauer J. Meinhardt K. W. Benz B. Kaufmann R. Hofmann A. Dornen 《Journal of Electronic Materials》1996,25(7):1082-1087
GaSb bulk single crystals with low acceptor concentration were grown from a bismuth solution by the traveling heater method.
The result is isoelectronic doping by Bi which gives a variation of the opto-electronic properties as a function of grown
length as well as a pronounced microscopic segregation. Photoluminescence spectra at 4K show a decrease of the natural acceptor
during growth, which is confirmed by Hall measurements. The electrical properties of this isoelectronic doped GaSb are hole
concentrations and mobilities of NA − ND = 1.7 × 1016 cm−3 and μ = 870 cm2Vs at room temperature and NA-ND = 1 × 1016 cm−3 and μ = 4900 cm2/Vs at 77K, respectively. The lowest p-type carrier concentration measured at 300K is NA − ND = 3.3 × 1015 cm−3 相似文献
82.
S. W. Short S. H. Xin A. Yin M. Dobrowolska J. K. Furdyna H. Luo 《Journal of Electronic Materials》1996,25(2):253-257
We report the observation of the quantum-confined Stark effect (QCSE) in ZnSe/ ZnCdSe single quantum wells grown by molecular
beam epitaxy, using photoluminescence. In our experiments the electric field was applied via a reverse-biased Schottky barrier
contact. To our knowledge, this is the first observation of the QCSE in any wide gap II-VI semiconductor heterostructure.
Significant red shifts, typically 10–15 meV, are detected before quenching. An associated reduction in the transition intensity,
consistent with the QCSE. is clearly observed. The dependence of these results will be discussed as a function of quantum
well depth and thickness. Complete quenching of the luminescence is observed with applied voltages as low as 5 V. In addition,
at lowest voltages, we also detect small blue shifts (up to 4 meV), which we attribute to the interaction between the externally
applied electric field and the built-in field of the structure. 相似文献
83.
C. Yuan T. Salagaj W. Kroll R. A. Stall M. Schurman C. Y. Hwang Y. Li W. E. Mayo Y. Lu S. Krishnankutty R. M. Kolbas 《Journal of Electronic Materials》1996,25(5):749-753
High quality InGaN thin films and InGaN/GaN double heterojunction (DH) structures have been epitaxially grown on c-sapphire
substrates by MOCVD in a production scale multi-wafer-rotating-disc reactor between 770 to 840°C. We observed that shroud
flow (majority carrier gas in the reaction chamber) is the key to obtaining high quality InGaN thin films. High purity H2 as the shroud flow results in poor crystal quality and surface morphology but strong photolumines-cence (PL) at room temperature.
However, pure N2 as the shroud flow results in high crystal quality InGaN with an x-ray full width at half maximum (FWHM)InGaN(0002) of 7.5 min and a strong room temperature PL peaking at 400 nm. In addition, InGaN/GaN single heterojunction (SH) and DH structures
both have excellent surface morphology and sharp interfaces. The full width at half maximum of PL at 300K from an InGaN/GaN
DH structure is about 100 meV which is the best reported to date. A high indium mole fraction in InGaN of 60% and high quality
zinc doped InGaN depositions were also achieved. 相似文献
84.
A. J. Steckl J. Devkajan W. J. Choyke R. P. Devaty M. Yoganathan S. W. Novak 《Journal of Electronic Materials》1996,25(5):869-873
The effect of post-implantation anneal on erbium-doped 6H-SiC has been investigated. 6H-SiC has been implanted with 330 keV
Er+ at a dose of 1 × 1013 /cm2. Er depth profiles were obtained by secondary ion mass spectrometry (SIMS). The as-implanted Er-profile
had a peak concentration of∼1.3 × 1018/cm3 at a depth of 770Å. The samples were annealed in Ar at temperatures from 1200 to 1900°C. The photoluminescence intensity
integrated over the 1.5 to 1.6 μm region is essentially independent of annealing temperature from 1400 to 1900°C. Reduced,
but still significant PL intensity, was measured from the sample annealed at 1200°C. The approximate diffusivity of Er in
6H SiC was calculated from the SIMS profiles, yielding values from 4.5 × 10−16 cm2/s at 1200°C to 5.5 × 10−15 cm2/s at 1900°C. 相似文献
85.
InxGa1-x As crystals with x = 0.25-0.08 have been successfully grown on GaAs seeds by a method of multicomponent zone melting growth.
Its alloy composition is found to be controlled by the growth temperature. Within an ingot, a good uniformity in the alloy
composition along the direction normal to the growth is also achieved. The alloy composition gradually changes along the growth
direction in the ingot, and this change is well explained by a temperature profile in the growth furnace. 相似文献
86.
B. A. Orner A. Khan D. Hits F. Chen K. Roe J. Pickett X. Shao P. R. Berger J. Kolodzey R. G. Wilson 《Journal of Electronic Materials》1996,25(2):297-300
The Ge1-yCy semiconductor alloy system offers promise as a material for use in heterostructure devices based on Si as well as other materials.
We have grown Ge1-y Cy alloys by solid source molecular beam epitaxy on Si substrates. Layer thicknesses ranged from 0.01 to 3 μm, and Auger electron
spectroscopy and secondary ion mass spectrometry indicated C fractions up to 3 at. %. Optical absorption in the near-infrared
region indicated a shift in the energy bandgap from that of Ge which was attributed to the effects of alloying. The dependence
of the bandgap on composition was consistent with linear interpolations of the Ge and C conduction band minimums. We observed
a fundamental absorption edge characteristic of an indirect bandgap material. Photoluminescence spectra at 11K of thick, relaxed
layers indicated single broad peaks near the expected bandgap energy. 相似文献
87.
Uniformity of deep levels in semi-insulating InP obtained by multiple-step wafer annealing 总被引:1,自引:0,他引:1
K. Kuriyama K. Ushiyama T. Tsunoda M. Uchida K. Yokoyama 《Journal of Electronic Materials》1998,27(5):462-465
The uniformity of deep levels in semi-insulating InP wafers, which have been obtained by multiple-step wafer annealing under
phosphorus vapor pressure, was studied using the thermally stimulated current (TSC) and photoluminescence (PL) methods. Only
three traps related to Fe, T0 (ionization energy Ei=0.19 eV), T1 (0.25 eV), and T2 (0.33 eV), probably forming complex defects, were observed in the wafer and they exhibited a relatively uniform distribution.
PL spectra relating to phosphorus vacancies observed in some regions of the wafer are correlated with a small TSC signal having
an ionization energy of 0.43 eV. 相似文献
88.
Tae-Yeon Seong Jung-Ja Yang Mee Yi Ryu Jong-In Song Phil W. Yu 《Journal of Electronic Materials》1998,27(5):409-413
Chemical beam epitaxial (CBE) GaxIn1?xP layers (x≈0.5) grown on (001) GaAs substrates at temperatures ranging from 490 to 580°C have been investigated using transmission electron diffraction (TED), transmission electron microscopy, and photoluminescence (PL). TED examination revealed the presence of diffuse scattering 1/2{111}B positions, indicating the occurrence of typical CuPt-type ordering in the GaInP CBE layers. As the growth temperature decreased from 580 to 490°C, maxima in the intensity of the diffuse scattering moved from ½{111}B to ½{?1+δ,1?δ,0} positions, where δ is a positive value. As the growth temperature increased from 490 to 550°C, the maxima in the diffuse scattering intensity progressively approached positions of $\frac{1}{2}\{\bar 110\} $ , i.e., the value of δ decreased from 0.25 to 0.17. Bandgap reduction (~45 meV) was observed in the CBE GaInP layers and was attributed to the presence of ordered structures. 相似文献
89.
S. Kim S. J. Rhee X. Li J. J. Coleman S. G. Bishop P. B. Klein 《Journal of Electronic Materials》1998,27(4):246-254
Site-selective photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopies carried out at 6K on the ∼1540
nm 4I13/2→4I15/2 emissions of Er3+ in Er-implanted GaN have revealed the existence of four different Er3+ sites and associated PL spectra in this semiconductor. Three of these four sites are excited by below-gap, impurity- or defect-related
absorption bands, with subsequent nonradiative energy transfer to the Er3+ 4f electrons; a fourth site is excited by direct Er3+ 4f shell absorption. PLE spectra obtained by selectively detecting Er3+ PL from each of the three sites pumped by broad below-gap absorption bands are compared with the PLE spectra of broad PL
bands attributed to implantation damage-induced defects in the Er-implanted GaN. This comparison enables us to distinguish
broad-band, below-gap optical excitation processes for Er3+ emission that are attributable to (1) absorption due to implantation damage-induced defects; (2) absorption due to defects
or impurities characteristic of the as-grown GaN film; and (3) an Er-specific absorption band just below the band gap which
may involve the formation of an Er-related isoelectronic trap. The two sites excited by impurity-or defect-related absorption
bands are also strongly pumped by above-gap excitation, while the sites pumped by the Er-related trap and direct 4f shell
absorption are not. This observation indicates that excitation of Er3+ luminescence in crystalline semiconductor hosts by either optical or electrical injection of electron-hole pairs is dominated
by trap-mediated carrier capture and energy transfer processes. These trap-mediated processes may also control the thermal
quenching of Er3+ emission in semiconductors. 相似文献
90.