共查询到18条相似文献,搜索用时 265 毫秒
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室温下在单晶Si中注入(0.6—1.5)at%的C原子,部分样品在C离子注入之前在其中注入29Si+离子产生损伤,然后在相同条件下利用高温退火固相外延了Si1-xCx合金,研究了预注入对Si1-xCx合金形成的影响.如果注入C离子的剂量小于引起Si非晶化的剂量,在950℃退火过程中注入产生的损伤缺陷容易与C原子结合形成缺陷团簇,难于形成Si1-xC关键词:
离子注入
固相外延
1-xCx合金')" href="#">Si1-xCx合金 相似文献
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室温下在单晶Si中注入(0.6—1.5)%的C原子,利用高温退火固相外延了Si1-xCx合金,研究了不同注入剂量下Si1-xCx合金的形成及其特征.如果注入C原子的浓度小于0.6%,在850—950℃退火过程中,C原子容易与注入产生的损伤缺陷结合,难于形成Si1-xCx合金相.随注入C原子含量的增加,C原子几乎全部进入晶格位置形成Si1-xCx
关键词:
1-xCx合金')" href="#">Si1-xCx合金
离子注入
固相外延 相似文献
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基于第一性原理密度泛函理论(DFT),广义梯度近似下的GGA+U方法,计算了Ge64-xCx(x=0~3)合金体系的能带结构和光学性质.计算结果显示,纯Ge的带隙宽度数值与实验值相符,为0.732 eV.在本文所研究的C浓度范围内Ge64-xCx(x=1~3)均转变成直接带隙,带隙随C原子的增加逐渐减小.光学性质的计算结果表明,C原子引入对所有的光学性质均产生影响,随着C浓度的增加Ge64-xCx合金的静态介电常数增大,在近红外区的吸收系数增大,且吸收光谱红移,对于Ge61C3吸收边延伸至中红外区.C原子掺杂使体系对光的利用率增强,Ge64-xCx合金的载流子寿命和光催化能力也随C浓度的变化而变化.Ge64-xCx合金有希望成为在近红外、中红外区域的光学材料. 相似文献
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文章考察了Mo-SiO2催化剂体系在丙烯歧化反应过程中的动态ESR波谱,发现在催化歧化反应过程中有两种Mo5+顺磁中心,一种为扰动八面体配位,g||=1.89,g⊥=1.94;另一种为扰动四棱锥配位,g||=1.86,g⊥=1.95。测得同位素95,97Mo5+的各向异性超精细耦合常数A||=90.3×10-4cm-1,A⊥=44.8×10-4cm-1;观测到反应产生的积炭信号,g≈2.0O2;氧阴离子自由基信号g1=2.018,g2=2.011,g3=2.005。用LCAO-MO理论对上述Mo5+的ESR波谱进行计算,求得分子轨道系数,发现并总结出△g||/△g⊥与△g成直线关系,并建议用△g||/△g⊥=4(△E(B2→E))/(△E(B2→B1)(β1/ε)2之比值作为衡量C4v扰动程度的尺度。 相似文献
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Aïssa Keffous Abdelhak Cheriet Noureddine Gabouze Yacine Boukennous Rabah Cherfi Lakhdar Guerbous Hamid Menari 《Applied Surface Science》2010,256(14):4591-4595
Hydrogenated amorphous SiC films (a-Si1−xCx:H) were prepared by dc magnetron sputtering technique on p-type Si(1 0 0) and corning 9075 substrates at low temperature, by using 32 sprigs of silicon carbide (6H-SiC). The deposited a-Si1−xCx:H film was realized under a mixture of argon and hydrogen gases. The a-Si1−xCx:H films have been investigated by scanning electronic microscopy equipped with an EDS system (SEM-EDS), X-ray diffraction (XRD), secondary ions mass spectrometry (SIMS), Fourier transform infrared spectroscopy (FTIR), UV-vis-IR spectrophotometry, and photoluminescence (PL). XRD results showed that the deposited film was amorphous with a structure as a-Si0.80C0.20:H corresponding to 20 at.% carbon. The photoluminescence response of the samples was observed in the visible range at room temperature with two peaks centred at 463 nm (2.68 eV) and 542 nm (2.29 eV). In addition, the dependence of photoluminescence behaviour on film thickness for a certain carbon composition in hydrogenated amorphous SiC films (a-Si1−xCx:H) has been investigated. 相似文献
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Hydrogenated amorphous silicon carbide (a-Si1-xCx:H) films were deposited by RF plasma enhanced chemical vapor deposition (PECVD) and subsequently annealed in N2 atmosphere at different temperatures. Systematic investigations of the deposition temperature and annealing effect on the film's properties, including film thicknesses, optical bandgap, refractive indexes, absorption coefficient (α), chemical bond configurations, stoichiometry and crystalline structures, were performed using ellipsometry, FTIR absorbance spectroscopy, Raman spectroscopy, XPS, and XRD. All of the results indicate that the structural and optical properties of the a-Si1-xCx:H film can be effectively engineered by proper annealing conditions. Moreover, molecular vibrational level equation was introduced to explain the peak shift detected by FTIR and Raman spectroscopy. 相似文献
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The hydrogen content in a-Si1−xGex:H thin films is an important factor deciding the density and the optical band gap. We measured the elemental depth profiles of hydrogen together with Si and Ge by elastic recoil detection analysis (ERDA) combined with Rutherford backscattering (RBS) using MeV He2+ ions. In order to determine the hydrogen depth profiles precisely, the energy- and angle-dependent recoil cross-sections were measured in advance for the standard sample of a CH3+-implanted Si substrate. The cross-sections obtained here are reproduced well by a simple expression based on the partial wave analysis assuming a square well potential (width: r0 = 2.67 × 10−13 cm, depth: V0 = −36.9 MeV) within 1%. For the a-Si1−xGex:H films whose elemental compositions were determined by ERDA/RBS, we measured the secondary ions yields of HCs2+, SiCs2+, H−, Si− and Ge− as a function of Ge concentration x. As a result, it is found that the useful yield ratios of HCs2+/SiCs2+, H−/Si− and Ge−/Si− are almost constant and thus the elemental depth profiles of the a-Si1−xGex:H films can be also determined by secondary ion mass spectrometry (SIMS) within 10% free from a matrix effect. 相似文献
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K. Rerbal I. Solomon J.-N. Chazalviel F. Ozanam 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,51(1):61-64
We have investigated the temperature dependence of
photoluminescence in hydrogenated amorphous silicon-carbon alloys
a-Si1-xCx:H prepared by glow discharge in the low-power regime.
The radiative recombination process, due to photocarriers trapped on
band-edge states, is in competition with the thermal escape of the
photocarriers into the mobility bands. The model gives a quantitative fit
with experiment, without any adjustable parameter, provided the width of the
band-edge distribution of states is taken as the width of the conduction
band only (measured by “photo-induced infra-red spectroscopy”) and not as
the Urbach energy, as it is usually assumed. 相似文献
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《Superlattices and Microstructures》1994,16(1):105-108
Results are presented concerning the characterization of p-Si/Si1-xGex/Si quantum wells (QW) by space charge spectroscopy. Analysis of potential barriers at the QW enables us to determine the valence band offset from such measurements. Admittance spectroscopy data of QWs with 30 nm undoped spacers, acceptor concentration NA of about 1017cm-3 in the cap and buffer layers, x=0.25 and a QW thickness in the range from 1 to 5 nm are in fair agreement with the proposed theoretical model. A decrease of the effective potential barriers due to hole tunneling via shallow acceptor states in the barrier is experimentally confirmed for 5 nm QW structures without spacers. 相似文献
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采用紧束缚方法对生长在GexSi1-x(001)衬底上的应变GaAs层的价电子能带结构和空穴的三次非线性光学极化率x(3)进行了计算结果表明,由于应变的存在,使GaAs层的空穴有效质量和价带态密度变小,而使偏振方向在(001)面内的三次非线性光学极化率xxxxx(3)变大.
关键词: 相似文献
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利用室温下压电调制反射光(PzR)谱技术系统测量了N掺杂浓度为0.0%—3%的分子束外延生长GaNxAs1-x薄膜,并对图谱中所观察的光学跃迁进行了指认.在GaN0.005As0.995和GaN0.01As0.99薄膜的PzR谱中观察到此前只在椭圆偏振谱中才看到的N掺杂相关能态E1+Δ1+ΔN.当N掺杂浓度达到
关键词:
压电调制反射光谱(PzR)
xAs1-x薄膜')" href="#">GaNxAs1-x薄膜
分子束外延(MBE) 相似文献