https://doi.org/10.1140/epjp/s13360-022-02409-z
Regular Article
Linear, third-order nonlinear and total absorption coefficients of a coupled InAs/GaAs lens-shaped core/shell quantum dots in terahertz region
Micro-Optoelectronic and Nanostructures Laboratory (LR99ES29), Physics Department, Scientific Faculty of Monastir, University of Monastir, Monastir, Tunisia
Received:
9
November
2021
Accepted:
21
January
2022
Published online:
23
February
2022
This work investigates the linear and nonlinear optical properties of coupled InAs/GaAs lens-shaped core/shell quantum dots. The discrete intra-band confined energy levels and their matching envelope wave functions were calculated implicitly via the finite difference method of second order. The absorption spectrum was adjusted in the terahertz region (THz) when pressure (P), temperature (T), wetting layer (WL), incident optical intensity (I), coupled width, and core and shell sizes assumed different values. Results showed that the absorption spectrum was strongly influenced by the spacer width between the coupled QDs and that a red-shift was achieved. Also, observations indicated the possibility of tailoring the shell’s width, consequently the encapsulation layer. In addition, the lens-shaped form of the considered system led to a red-shift of the absorption spectrum, and the absorption coefficient decreased in magnitude as compared to a spherical model. Moreover, the obtained results also revealed that the absorption spectrum underwent a blue-shift (red-shift) when temperature (pressure) increased. Furthermore, other significant results are that the absorption coefficient was influenced drastically as compared to a single core/shell. The considered structure could be useful in various applications in terahertz region.
© The Author(s), under exclusive licence to Società Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature 2022
