Tunable quantum confinement under hydrostatic pressure: Exploring electronic and optical outputs in Pöschl–Teller, Razavy and Woods–Saxon potentials

Abstract

To bridge the gap identified in the current literature, this comprehensive and quantitative investigation examines the tunability of excitonic spectra and light–matter interaction characteristics under hydrostatic pressure, employing three distinct confinement models: Pöschl–Teller, Razavy and Woods–Saxon potentials. The analysis is carried out within the framework of the effective mass approximation, leveraging the density matrix approach to capture the nonlinear behaviour of the resulting optical coefficients. In addition, an in-depth assessment of the parameters influencing the spatial configuration of the confinement potentials was conducted to determine their impact on oscillator strength and radiative lifetime, thereby revealing the underlying microscopic traits of each potential. This approach offers a pathway to regulate optical absorption and refractive index outputs, particularly regarding resonance peak positions and amplitudes. Our calculations revealed that for small well widths, binding energy rises steeply with pressure, whereas at larger widths, the curves decrease gradually and slightly intersect. Fixing specific confinement parameters also proved effective in amplifying the binding energy. A wider quantum well corresponds to an extended radiative lifetime, and this temporal parameter is further suppressed under elevated hydrostatic pressure. Conversely, the oscillator strength demonstrates an inverse tendency, showing notable enhancement at higher pressure values, especially under Woods–Saxon confinement where its amplification is most significant. Absorption and refractive index spectra can be effectively modulated by hydrostatic pressure and confinement-defining parameters. Pöschl–Teller potential shows blue-shifted peaks with dimensional scaling, unlike Razavy and Woods–Saxon, which exhibit red shifts. All three potentials experience red shifts and intensity loss under elevated pressure. Photobleaching is least prominent in the Razavy case under tuned conditions, but more significant in the others at equal irradiance.