Optical Properties of Conical Quantum Dot: Exciton-Related Raman Scattering, Interband Absorption and Photoluminescence

Abstract

The current work used the effective mass approximation conjoined with the finite element method to study the exciton states in a conical GaAs quantum dot. In particular, the dependence of the exciton energy on the geometrical parameters of a conical quantum dot has been studied. Once the one-particle eigenvalue equations have been solved, both for electrons and holes, the available information on energies and wave functions is used as input to calculate exciton energy and the effective band gap of the system. The lifetime of an exciton in a conical quantum dot has been estimated and shown to be in the range of nanoseconds. In addition, exciton-related Raman scattering, interband light absorption and photoluminescence in conical GaAs quantum dots have been calculated. It has been shown that with a decrease in the size of the quantum dot, the absorption peak has a blue shift, which is more pronounced for quantum dots of smaller sizes. Furthermore, the interband optical absorption and photoluminescence spectra have been revealed for different sizes of GaAs quantum dot.

Finite element 3D model of a double quantum ring: effects of electric and laser fields on the interband transition

“…We also studied the variation in oscillator strength of the interband transition and the corresponding radiative recombination time. Regarding the latter, a comparative reference to results reported in other articles for nanostructures of different shapes and sizes, found in various physical conditions, can be useful [42][43][44].…”

Photoluminescence spectra in GaAs biconical quantum dots

“…Furthermore, the geometrical adiabatic approximation 12 has been applied to theoretically explore strongly prolate and oblate lens-shaped, ellipsoidal, and conical QDs 13,14 . Nonetheless QDs with more trivial geometries, including conical QDs with similar base radius and height, present analytical challenges and are seldom explored theoretically 15,16 . This disparity between theoretical and experimental investigations of such structures underscores the need for a qualitative theoretical comprehension of wavefunction and energy spectrum behavior, facilitating the integration of QDs with non-trivial geometries into industrial applications.…”