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11.
Measurements of nH were performed. nH values showed a distinct increase at temperatures below ~90 K (1.1 μm n-InGaAs samples) and a decrease at temperatures below ~30 K (7 μm n-InGaAs samples), depending on the doping level. These trends might be related to the magnetoresistance (MR) of the n-InGaAs samples. The MR behavior of the n-InGaAs samples with respect to magnetic field and temperature was apparently dependent on the doping level. Two n-InGaAs samples, one of which had a thin InGaAs epilayer (1.1 μm) and the other with a thicker (7 μm) epilayer, showed interesting behavior at low temperature. Their behavior at magnetic fields of approximately −15000 to +15,000 G were determined. The resistivity ((ρG – ρ0)/ρ0) of the 1.1 μm sample was negative at temperatures lower than 30 K. 相似文献
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碲镉汞外延材料缺陷的研究进展 总被引:1,自引:1,他引:0
通过对近年来的部分国外文献进行归纳分析,介绍了碲镉汞(MCT)缺陷研究的现状.与其他类似的半导体相比,MCT以其显著的优势成为红外焦平面(FPA)器件中最为常用的窄带隙材料.MCT外延层中的缺陷可能会影响光敏元的性能,降低MCT焦平面器件的可用性.衬底类型、衬底晶向和生长期间的衬底温度等因素对MCT外延层的质量有明显影... 相似文献
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本文报道了采用含有InSb非晶过渡层的两步MBE生长技术,在GaAs(100)衬底上异质外延生长的InSb外延层材料特性及初步的器件性能。5μm厚的n型本征InSb外延层77K时的电子浓度和迁移率分别为:n~2.4×10 ̄(15)cm ̄(-3),μ~5.12×10 ̄4cm ̄2V ̄9-1)s ̄(-1),高质量InSb外延层的X射线双晶衍射半峰宽(FWHM)<150″。InSb表面的相衬显微形貌,InSb/GaAs界面的TEM形貌相和InSb外延层的红外透射谱等测试结果都肯定了MBEInSb外延层的质量。研究结果已基本达到目前国外同类研究水平。用MBE生长的n型InSb外延层薄膜首次制作了中波(3~5μm)多元光导线列器件,终测表明,器件的光导响应率较高R(V)~7800V/W,均匀性很好ΔR(V)/R(V)<7%,MBEInSb外延薄膜展示了良好的红外探测器应用前景。 相似文献
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首次用光调制反射光谱的实验测量方法,在~10K下对In_(1-x)Al_xSb(0≤x≤0.55)外延层的光跃迁E_1和E_1+△_1及其谱线展宽ω,进行实验测定。由测定结果,得到对E_1和E_1+△_1的弯曲参数分别为0.752eV和0.723eV。 相似文献
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Chloride-based fast homoepitaxial growth of 4H-SiC epilayers was performed on 4° off-axis 4H-SiC substrates in a home-made vertical hot-wall chemical vapor deposition (CVD) system using H2-SiH4-C2H4-HCl. The effect of the SiH4/H2 ratio and reactor pressure on the growth rate of 4H-SiC epilayers has been studied successively. The growth rate increase in proportion to the SiH4/H2 ratio and the influence mechanism of chlorine has been investigated. With the reactor pressure increasing from 40 to 100 Torr, the growth rate increased to 52 μm/h and then decreased to 47 μm/h, which is due to the joint effect of H2 and HCl etching as well as the formation of Si clusters at higher reactor pressure. The surface root mean square (RMS) roughness keeps around 1 nm with the growth rate increasing to 49 μm/h. The scanning electron microscope (SEM), Raman spectroscopy and X-ray diffraction (XRD) demonstrate that 96.7 μm thick 4H-SiC layers of good uniformity in thickness and doping with high crystal quality can be achieved. These results prove that chloride-based fast epitaxy is an advanced growth technique for 4H-SiC homoepitaxy. 相似文献
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用光助低压MOCVD进行ZnSe及ZnSe:N外延层生长,由发光光谱表明,在光助下生长的本征ZnSe外延膜具有高质量:ZnSe:N外延层中与N有关的深中心发射得到有效抑止,其p-ZnSe受主载流子深度达3×10^17cm^-3。在制备n-ZnSe/ZnCdSe-ZnSeQW/p-ZnSe结构中,在室温下观测到该二极管电脉冲下的蓝色电致发光(EL)。 相似文献
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Young Soo No Oleg Kononenko Yeon Sik Jung Won Kook Choi Tae Whan Kima 《Journal of Electroceramics》2006,17(2-4):283-285
ZnO films were grown on Al2O3 (1000) substrates without and with ZnO buffer layers by using radio-frequency magnetron sputtering. Atomic force microscopy
images showed that the surface roughness of the ZnO films grown on ZnO buffer layers annealed in a vacuum was decreased, indicative
of an improvement in the ZnO surfaces. X-ray diffraction patterns showed that the crystallinity of the ZnO thin films was
enhanced by using the annealed ZnO buffer layer in comparison with the film grown on without a buffer layer. The improvement
of the surface and structural properties of the ZnO films might be attributed to the formation of the Zn-face ZnO buffers
due to annealing in a vacuum. These results indicate that the surface and structural properties of ZnO films grown on Al2O3 substrates are improved by using ZnO buffer layers annealed in a vacuum. 相似文献