Enhancement of transition lifetime, linear and nonlinear optical properties in laterally coupled lens-shaped quantum dots for Tera-Hertz range

Makhlouf, D.; Choubani, M.; Saidi, F.; Maâref, H.

doi:10.1016/j.physe.2018.05.024

Cited by 14 publications

(6 citation statements)

References 22 publications

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“…In low-dimension structures, the strong confinement of the charge carriers leads to the quantification of the energy levels in such a way that both the absorption and emission spectrums, arising from the transition between the discrete electron and hole energy levels, are highly sensitive to QD shapes and sizes [8,9]. In the literature, the optical properties of excitons, such as lifetime, optical gain (OG), and oscillator strengths (OS), have been extensively studied for different types of QDs [10][11][12][13][14][15][16][17][18][19][20][21]. For example, S. Yilmaz et al [22] investigated the oscillator strengths for the intersubband transitions of the impurity in a CdS-SiO 2 QD.…”

Section: Introductionmentioning

confidence: 99%

Optical Gain of a Spherical InAs Quantum Dot under the Effects of the Intense Laser and Magnetic Fields

et al. 2023

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In quantum dots, where confinement is strong, interactions between charge carriers play an essential role in the performance of semiconductor materials for optical gain. Therefore, understanding this phenomenon is critical for achieving new devices with enhanced features. In this context, the current study examines the optical properties of an exciton confined in a spherical InAs quantum dot under the influence of magnetic and intense laser fields. We investigate the oscillator strength, exciton lifetime, and optical gain, considering the effects of both external fields. We also pay particular attention to the influence of quantum dot size on the results. Our calculations show that the two external fields have opposite effects on our findings. Specifically, the applied magnetic field increases the oscillator strength while the intense laser reduces it. In addition, the optical gain peaks are redshifted under the application of the intense laser, whereas the magnetic field causes a blueshift of the peak threshold. We also find that both external perturbations significantly influence the exciton lifetime. Our study considers the outcomes of both the exciton’s ground (1s) and first excited (1p) states. The theoretical results obtained in this study have promising implications for optoelectronic devices in the ∼3–4 μm wavelength range only through the control of quantum dot sizes and external perturbations.

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Section: Introductionmentioning

confidence: 99%

Optical Gain of a Spherical InAs Quantum Dot under the Effects of the Intense Laser and Magnetic Fields

et al. 2023

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“…Since the geometry of the system is complicated and the separation of variables in the Schrödinger equation does not take place even in the case of a scalar effective mass, it is necessary to use various approximate methods to describe optical properties of strongly oblate lens-shaped QD. Many works are devoted to this problem in which both the spectral and optical characteristics of the QDs under study are discussed [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ].…”

Section: Introductionmentioning

confidence: 99%

“…Moreover, it has been shown that the absorption coefficient decreased, and the absorption peaks shifted toward the higher energies in the presence of the impurity. In another paper [ 15 ], the effects of QD sizes, pressure, and temperatures on transitions lifetime, linear, and nonlinear absorption coefficients in terahertz range were theoretically investigated. The authors considered two laterally coupled InAs/GaAs lens-shaped QDs connected to a wetting layer.…”

Section: Introductionmentioning

confidence: 99%

Effects of an External Magnetic Field on the Interband and Intraband Optical Properties of an Asymmetric Biconvex Lens-Shaped Quantum Dot

et al. 2021

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The theoretical investigation of interband and intraband transitions in an asymmetric biconvex lens-shaped quantum dot are considered in the presence of an external magnetic field. The selection rules for intraband transitions are obtained. The behaviors of linear and nonlinear absorption and photoluminescence spectra are observed for different temperatures and magnetic field strengths. The second and third harmonic generation coefficients as a function of the photon energy are examined both in the absence and presence of an external magnetic field.

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“…Technologically, QDs have many potential applications in microelectronic and optoelectronic devices. In this respect, by employing different approaches and potential shapes, many researchers have studied the electronic structure [2–5], binding energies [6–8], optical properties [9–15], electric and magnetic field effects [16–25], and other physical properties [26–30] of single electron QDs. As well known, it is easy to obtain analytical solutions for single electron QDs.…”

Section: Introductionmentioning

confidence: 99%

Energy states, oscillator strengths and polarizabilities of many electron atoms confined by an impenetrable spherical cavity

Yakar

Çakır

Demir

et al. 2021

Int J of Quantum Chemistry

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We have calculated the ground and excited state energies and the orbital energies of three-electron atoms inside impenetrable spherical cavity. Energy eigenvalues and wavefunctions are calculated from the variational approximation method which is a combination of quantum genetic algorithm procedure and Hartree-Fock Roothaan method. In addition, the important parameters such as static and dynamic polarizability, oscillator strength and pressure have been investigated as perturbative. The results reveal that cavity radius and impurity charge have played an important role on the polarizability, the oscillator strength and pressure of the system. In addition, it is seen that when cavity radius is extremely large, all energies and the other physical parameters approach the values of a free space atom. As the dot radius decreases, the polarizability of system decreases due to the strong spatial confinement, but the pressure exerting on the system as the cavity radius R is shrunk increases. In addition, as the impurity charge increases, the oscillator strength decreases.

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Enhancement of transition lifetime, linear and nonlinear optical properties in laterally coupled lens-shaped quantum dots for Tera-Hertz range

Cited by 14 publications

References 22 publications

Optical Gain of a Spherical InAs Quantum Dot under the Effects of the Intense Laser and Magnetic Fields

Optical Gain of a Spherical InAs Quantum Dot under the Effects of the Intense Laser and Magnetic Fields

Effects of an External Magnetic Field on the Interband and Intraband Optical Properties of an Asymmetric Biconvex Lens-Shaped Quantum Dot

Energy states, oscillator strengths and polarizabilities of many electron atoms confined by an impenetrable spherical cavity

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