Absorption enhancement in thin-film photoluminescence layers with metal nanoparticles inter-coupling engineering

Abstract

We analyze the enhancement in optical absorption of a photoluminescence ZnS layer with embedded spherical metal nanoparticles (MNPs). Using introduced optical model based on the boundary element method (BEM), the so-called scattering cross-section over absorption cross-section (SCS/ACS) ratio has been defined that represents the strength of re-absorption by scattering. According to the collective behavior of the interacting plasmonic nanoparticles in an array, an optimum SCS/ACS is obtained for inter-particle distance over the particle diameter. This parameter gives a hint for the nanoparticle density and size in practical applications and is consistent for all of the metallic nanoparticles.

Phase function of a spherical particle when scattering an inhomogeneous electromagnetic plane wave

“…The new equations for the angular dependency of the scattering components (Equations 52-53) are easy to evaluate numerically using recurrence relations for the associated Legendre polynomials with argument zero (Equations 47-51). This solution seems a practical alternative to the numerical techniques for solving Maxwell's equations [36] and the more involved analytical solution [21,22] that one would otherwise employ.…”

“…Equation 21 also enables us to simplify the expressions for the scattering components S 1 and S 2 (35)(36). In fact, we can 5.…”

“…Scattering of an inhomogeneous wave by a particle in a nonabsorbing medium [18] is useful in total internal reflection microscopy [19], as this is based on the scattering by particles of an evanescent wave. Scattering by particles in absorbing media has especially received attention in random lasing [29][30][31][32] and solar cell absorption enhancement [33][34][35][36][37]. In the former area, the laser gain medium is often a dye solution with embedded particles, and researchers investigate the influence of scattering on the output character of the laser.…”