Excitonic States and Optical Transitions in CdS/HgS/CdS nanocylindrical Core/Shell/Shell Heterostructure
Paper ID : 1047-ICNS
Authors:
Volodya Artavazd Harutyunyan *1, David B Hayrapetyana2, Eduard M Kazaryan2
1Department of General Physics and Quantum Nanostructures, Russian -Armenian University
2Russain-Armenian University
Abstract:
Within the approximation of an isotropic effective mass, the states of electron-hole pair in the nanocylindrical layered CdS/HgS/CdS heterostructure are considered by the account of electron-hole electrostatic interaction in HgS quantized layer. The states of an interacting pair in a layer are considered in the moderate and weak quantization regimes. Processes involving both light and heavy holes are considered. The energy spectrum and envelopes of the wave functions of interacting electron-hole pair are computed in the structure under consideration. The dependence of the position of ground state energy level of the pair on the width of the well (layer thickness) is shown. The interband optical absorption and photoluminescence spectra are computed, when the system is a layered cylindrical quantum dot and when there is a free motion of the charge carriers along the symmetry axis. The dependence of the absorption coefficient and photoluminescence spectra on the energy of incident light have been investigated also. It is shown, that when electron-hole electrostatic interaction is taken into account, the band gap narrowing takes place. Accordingly, the absorption and luminescence peaks are shifted to the long-wavelength region. The values of this displacement is determined by the geometrical sizes of the sample.
Keywords:
Heterostructure; Quantum well; Exciton; Absorption; Luminescence
Status : Abstract Accepted (Oral Presentation)