热分解含硫金属有机配合物制备近红外PbS量子点

以Pb(NO₃)₂, Na(S₂CNEt₂)·3H₂O为反应物, 在去离子水中合成含硫金属有机配合物Pb(S₂CNEt₂)₂. 氩气保护下, 在油酸和十八烯混合溶液中热分解前躯体Pb(S₂CNEt₂)₂, 反应时间分别为30, 60, 90, 120 min, 获得PbS量子点样品a, b, c, d. 通过红外光谱分析和热重-差热等手段对前躯体进行表征, 证明配体Na(S₂CNEt₂)·3H₂O中的两个硫原子与Pb²⁺配位成功. PbS量子点样品X射线衍射和透射电子显微镜分析表明, 合成的PbS为类球形纯立方晶系PbS纳米晶; 对PbS量子点样品紫外-可见吸收光谱和光致发光谱进行研究发现, 吸收光谱和光致发光谱随着反应时间的增加顺序红移, 表明优化热分解反应时间可以调控PbS量子点的吸收光谱和光致发光谱. PbS量子点样品a发射峰在1080 nm, 与硅基太阳能电池相匹配, 可作为硅基荧光太阳能聚集器的荧光材料. 关键词： 热分解法 含硫金属有机配合物 PbS量子点 反应时间     

Optimization of the Effective Hamiltonian Parameters in a Semiempirical Method of Calculation of Complex Atomic Spectra

In a semiempirical investigation of complex atomic spectra a new approach is suggested, according to which the number of experimental points for optimization of parameters is to be increased. This is topical when the number of optimization parameters approaches the number of available experimental energy levels. The possible optimization of the effective Hamiltonian parameters has been investigated for the case where not experimental energy levels but rather the wavelengths (wavenumbers) of transitions between the levels of the studied configurations are used. For the spectra of Mo XVII and Fe VI agreement between optimized parameters in the conventional and new approaches has been established.     

Effective Mass of Strong-Coupling Bound Polaron in a Triangular Quantum Well Induced by Rashba Effect

In this paper, on the basis of Huybrechts＇ strong-coupling polaron model, the Tokuda modified linearcombination operator method and the unitary transformation method are used to study the properties of the strongcoupling bound polaron considering the influence of Rashba effect, which is brought by the spin-orbit （SO） interaction, in the semiconductor triangular quantum well （TQW）. Numerical calculation on the RbCI TQW, as the example, is performed. The expressions for the effective mass of the polaron as a function of the vibration frequency, the velocity, the Coulomb bound potential and the electron areal density are derived. Numerical results show that the total effective mass of the polaron is composed of three parts. The interactions between the orbit and the spin with different directions have different effects on the effective mass of the bound polaron.     

Effective Mass of Strong-Coupling Bound Polaron in a Triangular Quantum Well Induced by Rashba Effect

In this paper, on the basis of Huybrechts' strong-coupling polaron model, the Tokuda modified linear-combination operator method and the unitary transformation method are used to study the properties of the strong-coupling bound polaron considering the influence of Rashba effect, which is brought by the spin-orbit (SO) interaction, in the semiconductor triangular quantum well (TQW). Numerical calculation on the RbCl TQW, as the example, is performed. The expressions for the effective mass of the polaron as a function of the vibration frequency, the velocity, the Coulomb bound potential and the electron areal density are derived. Numerical results show that the total effective mass of the polaron is composed of three parts. The interactions between the orbit and the spin with different directions have different effects on the effective mass of the bound polaron.     

Rashba效应影响下三角量子阱中弱耦合极化子的有效质量

采用改进的线性组合算符和幺正变换相结合的方法,导出了三角量子阱中弱耦合极化子的有效质量。讨论了极化子速度、电声子耦合常数和电子面密度对极化子有效质量的影响。通过对GaAs材料的数值计算结果表明:因为电-声子耦合作用和Rashba效应的存在,发现弱耦合极化子的有效质量由两部分组成,而且弱耦合极化子的有效质量随电声子耦合常数、电子面密度和极化子速度都发生了分裂。     

The Measurement of Relative Complex Dielectric Constant by Means of an Automatic Slotted-Line System

This paper reports the measurement of relative complex dielectric constant of lost dielectric, by means of an automatic slotted-line system controlled with micro-computer IBM 80486 and by use of numerical method. The measuring principle, method, program and results are given. The measuring results shows that the way mentioned in this paper is successful, so it can be extended to MM-Wave band and other microwave band.