共查询到20条相似文献,搜索用时 109 毫秒
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本文用固相反应烧结制备出Li2Mo2O6多晶材料。经X射线分析、红外光谱和电子顺磁共振谱(EPR)的研究,确定了它的结构是Li2Mo2O4和MoO2两个晶相组成的烧结体。钼离子以四价状态存在于MoO2晶相结构中。采用交流阻抗谱分析了晶界与温度变化的相关性。测得了样品的ln(σ总T)-1/T 曲线是由两段直线和一段曲线所组成;总电导率化能σ27℃=1.36×10-3(Ω·cm)-1,σ115℃=1.49×10-3(Ω·cm)-1,σ300℃=9.71×10-3(Ω·cm)-1,σ370℃=2.42×10-3(Ω·cm)-1;电导活化能E1=0.043eV,E2=0.235eV,E平均=0.76eV。采用维格纳极化电池法测得电子电导率σe,σe27℃=2.240×10-5(Ω·cm)-1,σe300℃=4.476×10-3(Ω·cm)-1。实验证明,室温下材料为固体电解质,300℃附近为良好的离子与电子混合导体。
关键词: 相似文献
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在对周期性结构进行谐波分析的基础上,导出了非截面二维光子晶体排列矩形波导的本征值方程. 基于此方程,可以对该类光子晶体波导的所有可能模式进行分析. 分析认为,非截面二维光子晶体排列矩形波导内能存在的模式包括E(y),TEy,H(y)和TMy模式;改变波导高度,可以实现E(y)模式和H(y)模式与其他模式通带的完全分离. 然而改变任一结构参数,都不能使E(y)和H(y)的各个模式通带,以及E(y)1模式和H(y)1模式的通带完全隔离. 波导单模工作的带宽由E(y)1和E(y)2模式的低端截止频率决定.
关键词:
波导
光子晶体
本征值方程
模式 相似文献
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研究了磁场作用下石墨烯中电子与表面光学声子弱耦合情况下的极化子的性质。采用线性组合算符和Pekar变分法分别推导出了石墨烯中弱耦合极化子的基态能量E0、第一激发态能量E1和跃迁频率ω随磁场强度B和德拜截止波数kd之间的变化关系。数值计算结果表明,极化子的基态能量E0随磁场强度B变化的曲线(kd一定时)和E0随kd的变化曲线(B一定时)均会分裂成对称的两条,并且当B一定时E0的绝对值随kd的增加而增加。在kd一定时,极化子的第一激发态能量E1和跃迁频率ω均为磁场B的增函数;在B一定时,E1和ω均随kd的增加而增大。 相似文献
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用深能级瞬态谱(DLTS)技术测量了高温退火的Be和Si共注入的LEC半绝缘GaAs(无掺杂)。在多子脉冲作用下的Al/Be-Si共注LECSIGaAs肖特基势垒中,观测到E01(0.298),E02(0.341),E03(0.555)和E04(0.821)等四个电子陷阱以及两个主要的少子(空穴)陷阱H'03(0.54)和H″03(0.57)。两少子陷阱的DLTS信号具有若干特点,比如它们的DLTS·峰难于通过增宽脉冲达到最大高度;以及峰的高度强烈地依赖于温度等。这些现象可以用少子陷阱的少子俘获和热发射理论进行合理地解释。鉴于用DLTS技术测量这种陷阱的困难,我们用恒温电容瞬态技术测定它们的空穴表观激活能分别为0.54和0.57eV。它们是新观测到的和Be-Si共注SIGaAs有关缺陷。
关键词: 相似文献
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We have used deep level transient spectroscopy (DLTS), and Laplace-DLTS to investigate the defects created in antimony doped germanium (Ge) by sputtering with 3 keV Ar ions. Hole traps at EV+0.09 eV and EV+0.31 eV and an electron trap at EC−0.38 eV (E-center) were observed soon after the sputtering process. Room temperature annealing of the irradiated samples over a period of a month revealed a hole trap at EV+0.26 eV. Above room temperature annealing studies revealed new hole traps at EV+0.27 eV, EV+0.30 eV and EV+0.40 eV. 相似文献
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M. Asghar F. Iqbal S. Faraz V. Jokubavicius Q. Wahab M. Syväjärvi 《Physica B: Condensed Matter》2012,407(15):3041-3043
In this study deep level transient spectroscopy has been performed on boron–nitrogen co-doped 6H-SiC epilayers exhibiting p-type conductivity with free carrier concentration (NA–ND)∼3×1017 cm−3. We observed a hole H1 majority carrier and an electron E1 minority carrier traps in the device having activation energies Ev+0.24 eV, Ec −0.41 eV, respectively. The capture cross-section and trap concentration of H1 and E1 levels were found to be (5×10−19 cm2, 2×1015 cm−3) and (1.6×10−16 cm2, 3×1015 cm−3), respectively. Owing to the background involvement of aluminum in growth reactor and comparison of the obtained data with the literature, the H1 defect was identified as aluminum acceptor. A reasonable justification has been given to correlate the E1 defect to a nitrogen donor. 相似文献
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T. Ishida K. Maeda S. Takeuchi 《Applied Physics A: Materials Science & Processing》1980,21(3):257-261
Deformation-produced deep levels, both of electron and hole traps, have been studied using deep level transient capacitance
spectroscopy (DLTS) for an undopedn-type GaAs (HB grown) compressed at 440°C. Concentrations of two grown-in electron trap levels (E
c
−0.65eV andE
c
−0.74eV) and one grown-in hole trap level (E
v
+∼0.4eV) increase with plastic deformation, while that of a grown-in electron trap level (E
c
−∼0.3eV) decreases in an early stage of deformation. While no new peak appeared in the electron trap DLTS spectrum after plastic
deformation, in the hole trap DLTS spectrum a broad spectrum, seemingly composed of many peaks, newly appeared in a middle
temperature range, which may be attributed to electronic energy levels of dislocations with various characters. 相似文献
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P.N.K. Deenapanray H.H. Tan C. Jagadish 《Applied Physics A: Materials Science & Processing》2003,76(6):961-964
Defects created in rapid thermally annealed n-GaAs epilayers capped with native oxide layers have been investigated using
deep-level transient spectroscopy (DLTS). The native oxide layers were formed at room temperature using pulsed anodic oxidation.
A hole trap H0, due to either interface states or injection of interstitials, is observed around the detection limit of DLTS
in oxidized samples. Rapid thermal annealing introduces three additional minority-carrier traps H1 (EV+0.44 eV), H2 (EV+0.73 eV), and H3 (EV+0.76 eV). These hole traps are introduced in conjunction with electron traps S1 (EC-0.23 eV) and S2 (EC-0.45 eV), which are observed in the same epilayers following disordering using SiO2 capping layers. We also provide evidence that a hole trap whose DLTS peak overlaps with that of EL2 is present in the disordered
n-GaAs layers. The mechanisms through which these hole traps are created are discussed. Capacitance–voltage measurements reveal
that impurity-free disordering using native oxides of GaAs produced higher free-carrier compensation compared to SiO2 capping layers.
Received: 12 March 2002 / Accepted: 15 July 2002 / Published online: 22 November 2002
RID="*"
ID="*"Corresponding author. Fax: +61-2/6125-0381, E-mail: pnk109@rsphysse.anu.edu.au 相似文献
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The optical properties of deep hole traps H4 and H5 in p type and of the deep electron trap E11 in n type InP, introduced by electron irradiation, have been studied using deep level optical spectroscopy. Comparison of the optical threshold with the thermal activation energy of H5 level shows that it is highly relaxed with a Frank-Condon shift dFc = 0.45 eV. The electron level E11 is weakly relaxed and its optical cross section σ 0 is well accounted for by transitions to the Γ6c minimum. The optical absorption σp0 associated to level H4 shows two successive onsets at hν = 0.5 and hν = 1.2 eV which can be attributed to hole transitions to the Γ7–8 and to the L4–5 valence band extrema, respectively. The deduced Frank-Condon shift, dFc = 0.23 eV, agrees with the measured difference of 40 meV between its apparent activation energy Ea and its thermal activation energy ET. 相似文献
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In solar cells fabricated from boron‐doped Cz‐Si wafers minority and majority carrier traps were detected by deep level transient spectroscopy (DLTS) after so‐called “light‐induced degradation” (LID). The DLTS signals were detected from mesa‐diodes with the full structure of the solar cells preserved. Preliminary results indicate metastable traps with energy levels positioned at EV + 0.37 eV and EC – 0.41 eV and apparent carrier capture cross‐sections in the 10–17–10–18 cm2 range. The concentration of the traps was in the range of 1012–1013 cm–3. The traps were eliminated by annealing of the mesa‐diodes at 200 °C. No traps were detected in Ga‐doped solar cells after the LID procedure or below the light protected bus bar locations in B‐doped cells. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
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K. A. Nasyrov S. S. Shaĭmeev V. A. Gritsenko J. H. Han C. W. Kim J. -W. Lee 《Journal of Experimental and Theoretical Physics》2006,102(5):810-820
The kinetics of electron and hole accumulation in metal-oxide-nitride-oxide-semiconductor structures is studied. Experimental data are compared with a theoretical model that takes into account tunnel injection, electron and hole capture by traps in amorphous silicon nitride SiNx, and trap ionization. Agreement between experimental and calculated data is obtained for the bandgap width E g = 8.0 eV of amorphous SiO2, which corresponds to the barrier for holes Φh = 3.8 eV at the Si/SiO2 interface. The tunneling effective masses for holes in SiO2 and SiNx are estimated at m h * ≈ (0.4–0.5)m 0. The parameters of electron and hole traps in SiNx are determined within the phonon-coupled trap model: the optical energy W opt = 2.6 eV and the thermal energy W T = 1.3 eV. 相似文献
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We report the application of Deep Level Transient Spectroscopy (DLTS) in Hg1-xCdxTe, demonstrating for the first time the utilization of DLTS techniques in a narrow band-gap semiconductor, Eg < 0.40 eV. DLTS measurements performed on an n+-p diode with Eg (x=0.21, T=30 K) =0.096 eV have identified an electron trap with an energy of Ev + 0.043 eV and a hole trap at Ev + 0.035 eV. Measurements of trap densities, capture cross sections, and the close proximity of the electron and hole trap locations within the band-gap suggest that DLTS may be observing both the electron and hole capture at a single Shockley-Read recombination center. The trapping parameters measured by DLTS predict minority carrier lifetime versus temperature data to be comparable with the experimentally measured values. 相似文献
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The energy spectrum of charge carrier traps of semi-insulating n-type gallium arsenide has been investigated by the method of heat-stimulated currents and the parameters characterizing these traps have been estimated. Trap acceptor levels with energies 0.37, 0.41 and 0.17, 0.28, 0.32, 0.34, 0.38, 0.40 eV have been found for samples with the specific resistivity 2.7 · 107 and 1.6 · 108 · cm, respectively. The results obtained are well explained within the framework of the theory of a compensated semiconductor.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 11, pp. 22–26, November, 1971.The authors are grateful to A. P. Vyatkin, V. G. Voevodin, and E. V. Kozeev for kindly providing the gallium arsenide crystals and stimulating the research. 相似文献