共查询到16条相似文献,搜索用时 734 毫秒
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在(CdSe)1(ZnSe)3/ZnSe短周期超晶格多量子阱中,根据一维线性链模型计算的结果与实验结果的比较表明,我们在不同的共振条件下分别观察到了来自多量子阱的阱中和垒中ZnSe限制纵光学声子模的Raman散射。与GaAs/AlAs量子阱的偏振选择定则不同,在共振条件下,我们在两种偏振配置下都观察到了阱中ZnSe限制模LO1,并认为这种不同可能来源于样品特殊的电子子带结构和光学声子行为。
关键词: 相似文献
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采用脉冲激光沉积(PLD)镀膜技术在倾斜10°的LaAlO3(100)单晶衬底上制备了(SrTiO3)n/(SrTi0.8Nb0.2O3)m系列超晶格.在超晶格薄膜的XRD图谱中清楚地观察到周期调制的卫星峰结构.从卫星峰的分布计算了超周期,进而得到了在生长SrTiO3和SrTi0.8Nb0.2<
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3)n/(SrTi0.8Nb0.2O3)m]20/LAO(100)超晶格')" href="#">[(SrTiO3)n/(SrTi0.8Nb0.2O3)m]20/LAO(100)超晶格
激光感生热电电压
各项异性Seebeck系数
原子层热电堆 相似文献
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从第一性原理出发,在局域密度近似下,采用基于密度泛函理论的平面波超软赝势计算方法系统地研究了高压对BaHfO3电子结构与光学性质的影响.能带结构分析表明;无压强和施加正压强作用时,BaHfO3为直接带隙绝缘体,而施加负压强时,BaHfO3则转变为间接带隙半导体;BaHfO3的带隙随压强增加而减小,且具有明显的非线性关系.对光学性质的分析发现:施加正压强后,光学吸收带边产生蓝移;负压强作用时介电函数虚部尖峰减少,光学吸收带边产生红移;施加压强后BaHfO3的静态介电常数和静态折射率均增大.上述研究表明施加高压有效调制了BaHfO3的电子结构和光学性质,计算结果为BaHfO3光电材料的设计与应用提供了理论依据. 相似文献
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考虑到应力对超薄层(GaP)1/(InP)1(111)结构中Ga-P和In-P键长的作用为均匀分布的情况,本文提出在紧束缚近似下,将应力的影响直接反映到Harrison的交迭积分项中,并利用Recursion方法全面计算了由Keating模型确定的稳定(GaP)1/(InP)1(111)超晶格体内和表面的电子结构,结果表明,这种材料的带隙为1.88eV,它比体材料GaP(2.91eV)和InP(1.48eV)的平均值小
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利用第一性原理计算了立方相萤石TiO2的晶胞参数,能带结构和电子态密度.结果显示萤石TiO2属于间接带隙半导体材料,其间接禁带宽度(Γ→X)Eg为2.07eV,比常见的金红石和锐钛矿TiO2的禁带宽度窄.为了更清楚地了解萤石的光学性质,利用Kramers-Kronig色散关系,分别对萤石和金红石TiO2的复介电常数、吸收率等参数进行了计算,并将二者结果做了
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2')" href="#">萤石结构TiO2
密度泛函理论
能带结构
光学性质 相似文献
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The optical and electronic properties of (GaAs)n/(InAs)n superlattices are calculated by means of LMTO-ASA method. The too small band gap problem of bulk material and superlattices is corrected by adding to the effective potentials an additional external potential that is sharply peaked at the atomic sites. The results show that the optical properties of GaAs/InAs(001) superlattices are about average of that of two bulks of GaAs and InAs. 相似文献
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采用射频磁控溅射方法在(001)SrTiO3衬底上制备(001)取向的(BiFeO3)25/(La0.7Sr0.3MnO3)25多层膜.光学测试结果表明,1.3-2.1 eV范围内,相对于衬底而言多层膜光吸收增强; BiFeO3的带隙为2.7 eV. 另外,结合绝缘介质导电模型分析了所测得的电流-电压数据,在所测试的温度及电压下,所制备的(BiFeO3)25/(La0.7Sr0.3MnO3)25多层膜的导电机理由空间电荷限制电导主导.
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多层膜
吸光度
空间电荷限制电导 相似文献
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M. MerabetD. Rached R. Khenata S. BenaliaB. Abidri N. BettaharS. Bin Omran 《Physica B: Condensed Matter》2011,406(17):3247-3255
An accurate ab initio full potential linear muffin-tin orbital method has been used to investigate the structural, electronic and optical properties of BP, BAs and their (BP)n/(BAs)n superlattices (SLs). The exchange-correlation potential is treated with the local density approximation of Perdew and Wang (LDA-PW). The calculated structural properties of BP and BAs compounds are in good agreement with available experimental and theoretical data. It is found that BP, BAs and their alloys exhibit an indirect fundamental band gap. The fundamental band gap decreases with increasing the number of monolayer n. The optical properties show that the static dielectric constant significantly decreases in superlattices compared to their binary compounds. 相似文献
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《Solid State Communications》1988,65(11):1285-1290
Using the empirical tight binding method we have investigated the electronic properties of the Sin/Gen(001) strained superlattices as a function of the superlattice periodicity and the band misfit. For n ≥ 4 we have found that first and second conduction band states are localized in Si. The hole states localized in Ge appear for n ≥ 4. The difference between the direct and indirect band gaps is reduced from 2.01 eV for bulk Si to 0.01 eV for n=6 which can be considered to be quasi-direct. For the cases n=6 and n=8, the band gap might become direct for large values of band misfit. 相似文献