Exciton photoluminescence in resonant quasi-periodic Thue–Morse quantum wells

Abstract

This Letter investigates exciton photoluminescence (PL) in resonant quasi-periodic Thue-Morse quantum wells (QWs). The results show that the PL properties of quasi-periodic Thue-Morse QWs are quite different from those of resonant Fibonacci QWs. The maximum and minimum PL intensities occur under the anti-Bragg and Bragg conditions, respectively. The maxima of the PL intensity gradually decline when the filling factor increases from 0.25 to 0.5. Accordingly, the squared electric field at the QWs decreases as the Thue-Morse QW deviates from the anti-Bragg condition.

Bifractal focusing and imaging properties of Thue–Morse Zone Plates

“…The new diffractive lenses are based on the deterministic Thue-Morse sequence. This sequence has been applied in several branches of Physics, as for example in the context of photonic crystals [15], quantum wells [16], metamaterials [17] and graphene superlattices [18]. Here we present the first diffractive lenses contructed using this formalism.…”

Twin extra-high photoluminescence in resonant double-period quantum wells

“…In particular, in terms of light emission, the results have shown that the PL intensity in a Fibonacci quantum well (FQW) is significantly stronger than that in a PQW, not only under the Bragg condition, but also under the anti-Bragg condition [23,26]. It has also been found that the properties of PL intensity in a Thue-Morse quantum well (TMQW) are similar to those in a PQW [5]. Therefore, the PL properties of a TMQW and a FQW are quite different, even though they are both quasi-periodic QWs.…”

“…The maximum PL intensity in a DPQW is also stronger than that in a periodic QW under the anti-Bragg condition and that in a Fibonacci QW. Although the peaks of the squared electric field for the twin PL are both located near the QWs, their field profiles are distinct.Resonant photonic crystals have received a great deal of interest because of their optical properties and their potential application in various optical devices [1][2][3][4][5]. Because of their advantages in terms of fabrication and cost, one-dimensional resonant photonic crystals based on multiple quantum wells (QWs) with a periodic arrangement, namely resonant periodic quantum wells (PQWs), have attracted much attention with regard to their optical properties during the past decades [6][7][8].…”

“…The intensity of the luminescence emitted from the DPQW depends on the incident angle, the contribution of the exciton to the light polarization, and the generation order and the spacing thickness of the structure. This is calculated based on the introduced resonant source term, the radiation boundary condition, and the following two assumptions: one, that there is no correlation between the source functions in the QWs and two, that the distribution of the direction of the noncoherent exciton polarization is isotropic in the plane of the structure [5,7,23]. This study only considers the PL spectra radiated to the left side of the DPQWs and along the growth direction, which are described as the summation of radiation created by each source in a noncoherent manner, expressed as Iω 4ΞjqS∕φ 1 j 2 P N j1 jℑ j ωj 2 .…”

“…This study only considers the PL spectra radiated to the left side of the DPQWs and along the growth direction, which are described as the summation of radiation created by each source in a noncoherent manner, expressed as Iω 4ΞjqS∕φ 1 j 2 P N j1 jℑ j ωj 2 . The spectral density Ξ is relevant to the Fourier transformed source correlation, q is the light wave vector, S is related to the exciton susceptibility, φ 1 is the projection of the exciton wave function on the even solution, u 1 , of d 2 Ez∕dz 2 q 2 Ez 0, and ℑ j ω is a Green's function depicting the field radiated by each source [5,7]. The transmission, reflection, and absorption spectra of the structures are obtained by the transfer matrix method [7,12,23].…”