Effect of Quantum Barrier Thickness on the Optical Properties of Triple Triangular GaAs/AlGaAs Quantum Wells
Abstract
This study investigates the electronic and optical properties of a GaAs/AlxGa1-xAs triple triangular quantum well (QW) structure, focusing on the 2-4 and 3-4 intersubband transitions. By varying the right barrier (RB) thickness from 0 to 6 nm, the impact on wave function localization, energy levels, dipole moment matrix elements, absorption coefficients, and refractive index changes was analyzed using a finite element-based Schrödinger solver. Quantitative results indicate that increasing the RB breaks the symmetry of the potential, enabling the 2-4 transition and causing variations in absorption coefficients, which peak at 4 nm before declining. The 3-4 transition exhibits a higher and more stable total absorption coefficient compared to the 2-4 transition, ranging from 1100 to 1125 cm⁻¹. Additionally, the total refractive index changes for the 3-4 transition remain constant (±0.006 to ±0.009), while the 2-4 transition shows more variation (±0.001). Qualitatively, the 3-4 transition's stability and minimal energy difference from the 2-4 transition make it a more promising candidate for terahertz device applications, particularly where RB thickness constraints are present. These findings underscore the importance of barrier engineering in optimizing QW-based devices for advanced semiconductor application.
Keywords
GaAs, AlGaAs, Quantum Well, Absorption Coefficient, Refractive Index Change
Supporting Institution
Projeye bağlı yayın değildir.
Ethical Statement
Herhangi bir etik kurul izni gerektirmemektedir.
References
- [1] Ozturk E., Sari H., Sokmen I., The dependence of the intersubband transitions in square and graded QWs on intense laser fields, Solid State Communications, 132(7) (2004) 497-502.
- [2] Sayrac H., Jaouane M., Ed-Dahmouny A., Sali A., Ungan F., Modulation of nonlinear optical rectification, second, and third harmonic generation coefficients in n-type quadruple δ-doped GaAs quantum wells under external fields, Physica B: Condensed Matter, 690 (2024) 416252.
- [3] Restrepo R.L., Castaño-Vanegas L.F., Martínez-Orozco J.C., Morales A.L., Duque C.A., Mid-Infrared linear optical transitions in delta-doped AlGaAs/GaAs triple-quantum well, Applied Physics A, 125(1) (2018) 31.
- [4] Martínez-Orozco J.C., Mora-Ramos M.E., Duque C.A., The nonlinear optical absorption and corrections to the refractive index in a GaAs n-type delta-doped field effect transistor under hydrostatic pressure, Physica Status Solidi B, 249(1) (2012) 146-152.
- [5] Ozturk O., Alaydin B.O., Altun D., Ozturk E., Intense laser field effect on the nonlinear optical properties of triple quantum wells consisting of parabolic and inverse-parabolic quantum wells, Laser Physics, 32(3) (2022) 035404.
- [6] Alaydin B.Ö., Optical Properties of Gaas/Alxga1-xas Superlattice Under E-Field for Quantum Cascade Laser Application, Gazi University Journal of Science, 34(4) (2021) 1179-1191.
- [7] Dakhlaoui H., Linear and nonlinear optical absorption coefficients and refractive index changes in GaN/AlxGa(1−x)N double quantum wells operating at 1.55 μm, Journal of Applied Physics, 117(13) (2015).
- [8] Salman Durmuslar A., Investigation on nonlinear optical properties of symmetric and asymmetric double V-shaped AlxGa1-xAs/GaAs potential wells with structural parameters and external electromagnetic fields, Philosophical Magazine, 103(9) (2023) 872-891.
- [9] Rodríguez-Magdaleno K.A., Martínez-Orozco J.C., Rodríguez-Vargas I., Mora-Ramos M.E., Duque C.A., Asymmetric GaAs n-type double δ-doped quantum wells as a source of intersubband-related nonlinear optical response: Effects of an applied electric field, Journal of Luminescence, 147 (2014) 77-84.
- [10] Barseghyan M.G., Hakimyfard A., López S.Y., Duque C.A., Kirakosyan A.A., Simultaneous effects of hydrostatic pressure and temperature on donor binding energy and photoionization cross section in Pöschl– Teller quantum well, Physica E: Low-dimensional Systems and Nanostructures, 42(5) (2010) 1618-1622.