Linear and second-order optical response of III-V monolayer superlattices

Abstract

We report the first fully self-consistent calculations of the nonlinear optical properties of superlattices. The materials investigated are mono-layer superlattices with GaP grown on the the top of InP, AlP and GaAs (110) substrates. We use the full-potential linearized augmented plane wave method within the generalized gradient approximation to obtain the frequency dependent dielectric tensor and the second-harmonic-generation susceptibility. The effect of lattice relaxations on the linear optical properties are studied. Our calculations show that the major anisotropy in the optical properties is the result of strain in GaP. This anisotropy is maximum for the superlattice with maximum lattice mismatch between the constituent materials. In order to differentiate the superlattice features from the bulk-like transitions an improvement over the existing effective medium model is proposed. The superlattice features are found to be more pronounced for the second-order than the linear optical response indicating the need for full supercell calculations in determining the correct second-order response.

Influence of halide composition on the structural, electronic, and optical properties of mixedCH3NH3Pb(I1−xBrxJong1, Yu2, Ri3 et al. 2016Phys. Rev. B14811860View full textAdd to dashboardCite

“…Our calculations gave the formula E g (x) = In order to directly estimate the light harvesting capability of PSCs, we next describe the photoabsorption coefficients of these mixed halide perovskites with different Br contents, which can be obtained from Equation (5) using the real and imaginary parts of frequency dependent dielectric constants, calculated within DFPT [42]. In Figure 4, we present the photoabsorption coefficients to be functions of photon energy as increasing the Br content.…”

“…Using the optimized unit cells, the frequency dependent dielectric constants, ε(ω)=ε 1 (ω)+iε 2 (ω), were calculated within the density functional perturbation theory (DFPT) [42]. Then, the photoabsorption coefficients as a function of frequency ω can be obtained using the following equation,…”

Laser Induced Multiphoton Effects in Nano-Graphene Molecules

“…c † and c are the electron creation and annihilation operators. e r is the dipole operator, whose matrix elements are computed from the single-electron momentum operator through [22] …”

Second-Harmonic Generation

“…Understanding the influence of this competition on the final response has become then a mandatory task for practical applications of Si/CaF 2 and the interfaces in general [21,22,54,67]. Therefore, a great effort has been devoted to analyze these states.…”

“…(5.2) and represents the standard approach used in literature so far [13,22,50,54,57,70,152]. It is obtained treating the electrons as non-interacting particles.…”