Emission and percolation of excitons in dense sensembles of quantum dots on the spherical surface

被引：4

作者：

Bondar, N. V. ^{[1
]}

Brodyn, M. S. ^{[1
]}

Yermolayeva, Yu. V. ^{[2
]}

Tolmachev, A. V. ^{[2
]}

机构：

[1] Natl Acad Sci Ukraine, Inst Phys, Kiev, Ukraine

[2] Natl Acad Sci Ukraine, Inst Single Crystals, Kharkov, Ukraine

来源：

PHYSICA E-LOW-DIMENSIONAL SYSTEMS & NANOSTRUCTURES | 2011年 / 43卷 / 10期

关键词：

PHOTOLUMINESCENCE; NANOCOMPOSITES; CLUSTERS;

D O I：

10.1016/j.physe.2011.06.032

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

We study core/shell heterostructures in which a core (SiO2) is overcoated with a shell of ZnO quantum dots, randomly distributed on the sphere surface with the surface filling factor P similar to 0.45. Due to the high surface energy of SiO2 spheres, ZnO quantum dots have the shape of disks in which, in spite of the large radii, quantum size effects of excitons are retained. The height of ZnO disks estimated by the effective mass approximation is comparable with the exciton diameter in bulk ZnO. Analysis of optical spectra has shown that, at the given density of ZnO quantum dots, the exciton system is above the percolation threshold. The quantitative parameters characterizing such phenomenon are obtained using the elements of percolation theory and the topology of the samples. (C) 2011 Elsevier B.V. All rights reserved.

引用

页码：1882 / 1886

页数：5

共 16 条

[1] Evolution of excitonic states in two-phase systems with quantum dots of II-VI semiconductors near the percolation threshold [J].