Optimal trapping of monochromatic light in designed photonic multilayer structures

Abstract

Abstract. We devise an optimised bi-component multi-layered dielectric stack design to enhance the local irradiance for efficient photovoltaic upconversion materials. The field intensity profile throughout the photonic structure is numerically optimized by appropriate tuning of the individual layers' thicknesses. The optimality of the thus inferred structure is demonstrated by comparison with an analytically derived upper bound. The optimized local irradiance is found to increase exponentially with the number of layers, its rate determined by the permittivity ratio of the two material components. Manufacturing errors which induce deviations from the optimised design are accounted for statistically, and set a finite limit to the achievable enhancement. Notwithstanding, realistic assumptions on manufacturing errors still suggest achievable irradiances which are significantly larger than those obtained with the recently proposed Bragg stack structures.

Experimental validation of a modeling framework for upconversion enhancement in 1D-photonic crystals

“…Most random thickness variations of single layers lead to a decrease in energy density in the active layers and therefore to a reduced UCPL rel . For particular designs though, non-periodic thickness variations of single layers can lead to an additional strong increase of the energy density in the active layers 55 , which consequently leads to an additional increase in UCPL rel . This might contribute to a maximum measured enhancement of 4.1 for λ design = 1844 nm.…”

Cooperative scattering of scalar waves by optimized configurations of point scatterers

“…If the wave is scattered back and forth many times between a few scatterers, this may lead to a strong enhancement of the local field intensity in the vicinity of these scatterers. These local field enhancements are interesting for technological applications, since they can be used to increase the efficiency of solar cells or other optical devices [4,5], and have been observed in specifically tailored nanostructured materials consisting of, e.g. metallic nanoantennas [6], nanospheres [7] or nanoparticles [8].…”

Scattering theory of efficient quantum transport across finite networks

“…Excitation transport across finite, discrete and disordered networks [1][2][3] defines an abstract model for a variety of quantum transport problems, with applications to realistic physical scenarios which reach from natural or artificial light harvesting [4] to the physics of cold Rydberg gases [5][6][7]. Beyond fundamental aspects of disorder-induced localisation on discrete networks, this setting also defines an interesting incidence of quantum control in the presence of (and, possibly, through) disorder, which, by the very nature of disordered systems, enforces a statistical approach.…”