Excitonic transitions in spherical inhomogeneous QD, new monocolor nanosource

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• 作者：F. Benhaddou^a ; I. Zorkani^a ; ^{izorkani@hotmail.com" class="auth_mail" title="E-mail the corresponding author} ; A. Jorio^a ; E. Feddi^b
• 关键词：Quantum confinement effect ; Excitonic transitions ; Quantum dot ; Inhomogeneous QD ; Two level system ; Binding energy
• 刊名：Physica B: Physics of Condensed Matter
• 出版年：2015
• 出版时间：15 November 2015
• 年：2015
• 卷：477
• 期：Complete
• 页码：100-104
• 全文大小：1316 K

文摘

We study in this investigation the excitonic transitions in new spherical nanosystems also called inhomogeneous quantum dots IQD. They are promising in many technological applications: photovoltaic, LED, QD Laser and quantum computing. The excitonic binding energy significantly increases; which gives them greater stability at room temperature. The well-semiconductors in these nanostructures become luminescent under dual control core–well, in a wide spectral range from near UV to near and medium infrared IR. These optical properties enriched the field of IQD which generally have a high quantum efficiency and high photostability.

The IQD presented are made out off ZnSe/HgS/ZnSe; CdS/GaSb/CdS; ZnS/HgS/ZnS and CdS/InSb/CdS modeled by a spherical well with infinite potential. Our theoretical investigation shows that the high degree of confinement in the well retains the 1s_e−1p_e−2s_e$1s_e-1p_e-2s_e$ (1s_h−1p_h−2s_h$1s_h-1p_h-2s_h$) order, guarantees excitonic transitions and isolates the ground state 1s_e−1s_h$1s_e-1s_h$ ($E_{2s}^{e,h}-E_{1p}^{e,h}$ can be exceed 6 eV).

The strong confinement provided by the infinite barrier, reduces the population relaxation and limit the coupling between the well and the electrostatic environment. These results qualify the nanostructure as a monocolor source and a system of two levels.