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101.
102.
Diamine的光、电性质及其在有机薄膜电致发光器件中的应用 总被引:5,自引:1,他引:4
合成了芳香族二胺类衍生物(diamine),测定了它的光、电性质.制备了diamine作为空穴传输层的二层结构有机薄膜电致发光器件,使器件的发光亮度相对单层器件有了很大的提高.并用不同区域掺杂的方法,探讨了电致发光机理.分析、讨论了激子的形成和复合区域,较好地解释了单、双层器件的不同的电流电压关系和不同的亮度电压关系.从激子的扩散方程出发,对双层掺杂器件的发光强度比数据进行了拟合,确证了激子的扩散模式. 相似文献
103.
纳米材料二氧化锡的制备和激子态光学特性研究 总被引:4,自引:1,他引:3
报道纳米材料二氧化锡的制备和室温下激子态光学特征,应用弱量子限域下激子响应模型对结果进行了解释。 相似文献
104.
105.
电子自旋共振(ESR)实验间接表明,γ射线辐照能在室温下在BaF2微晶中产生Frenkel激子这样的元激发,此元激发受热在150℃以下消失。γ射线辐照使BaF2微晶中F-离子上的2P电子跃迁到外层轨道,并与2P轨道的空穴形成紧束缚的电子-空穴对——Frenkel激子。激子中的电子受热脱离F原子,这种晶格上的F0是ESR可探测的顺磁色心点缺陷——Vk心。受γ射线辐照的BaF2微晶中含有Frenkel激子,受热时Frenkel激子湮灭。Vk心增多的现象,表现为随温度增高Vk心的ESR信号增强的反常现象。 相似文献
106.
Arshak L. Vartanian Mkrtich A. Yeranosyan Albert A. Kirakosyan 《Physica E: Low-dimensional Systems and Nanostructures》2005,27(4):447-456
Using a variational technique, the effect of electron-longitudinal optical (LO) phonon interaction on the ground and the first few excited states of a hydrogenic impurity in a semiconductor quantum wire of rectangular cross section under an external electric field is studied theoretically for the impurity atom doped at various positions. The results for the binding energy as well as polaronic correction are obtained as a function of the size of the wire, the applied uniform electric field and the position of the impurity. It is found that the presence of optical phonons changes significantly the values of the impurity binding energies of the system. Taking into account the electron–LO phonon interaction the 1s→2py and 1s→2pz transition energies are calculated as a function of applied electric field for different impurity positions. 相似文献
107.
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109.
We describe an algorithm for the asymmetric traveling salesman problem (TSP) using a new, restricted Lagrangean relaxation based on the assignment problem (AP). The Lagrange multipliers are constrained so as to guarantee the continued optimality of the initial AP solution, thus eliminating the need for repeatedly solving AP in the process of computing multipliers. We give several polynomially bounded procedures for generating valid inequalities and taking them into the Lagrangean function with a positive multiplier without violating the constraints, so as to strengthen the current lower bound. Upper bounds are generated by a fast tour-building heuristic. When the bound-strengthening techniques are exhausted without matching the upper with the lower bound, we branch by using two different rules, according to the situation: the usual subtour breaking disjunction, and a new disjunction based on conditional bounds. We discuss computational experience on 120 randomly generated asymmetric TSP's with up to 325 cities, the maximum time used for any single problem being 82 seconds. This is a considerable improvement upon earlier methods. Though the algorithm discussed here is for the asymmetric TSP, the approach can be adapted to the symmetric TSP by using the 2-matching problem instead of AP.Research supported by the National Science Foundation through grant no. MCS76-12026 A02 and the U.S. Office of Naval Research through contract no. N0014-75-C-0621 NR 047-048. 相似文献
110.
Sambhu N Datta 《Pramana》1984,22(2):L125-L130
Pseudopotential is used as a formal operator to write the exact time-dependence of a pseudoexciton and hence that of an initial
excitation spatially localized in a crystal. The exponential operator where pseudopotential occurs at the argument is readily
evaluated using the property of projection operators. Migration of an initially localized excitation is of considerable experimental
importance and can be of conceptual use since it should eventually generate the characteristics of a migrating exciton. From
the formal time-dependence of a localized excitation, its spread with time can be calculated with relative ease. In a concurrent
discussion, the previous work of Merrifield (1958) on the propagation of excitation is criticized and an error is pointed
out. The spread, however, remains wavelike and is not dissipative in the absence of a collisional mechanism. 相似文献