Microstructured surfaces for enhanced transmission

Autor: Fridolin Okkels, Aliaksandra Ivinskaya, René Bergmann, Jan Kafka, Mogens Jakobsen
Rok vydání: 2014
Předmět:
Zdroj: 2014 8th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics.
Popis: Binary microstructures are used to increase transmission of silicon (Si) surfaces in the infrared (IR) range. We consider hexagonal and square lattices with square and round pillars with the finite-difference frequency-domain (FDFD) method. In agreement with theory and previous publications, the height needed to improve transmission for all geometries is given by λ/4√n Si where n Si is the refractive index of Si. Optimal size of microstructures is found through rigorous simulations. Different effective medium theories (EMTs) are compared whether they can predict this optimal size. Zero-order EMT appears to be one of the best choices, another good choice is volume averaging of refractive index. Manufacture-related issues are also discussed: for example, choice of bigger period is preferential as it gives better stability of the transmission curve if variations of pillar diameter and height occur from batch to batch during fabrication.
Databáze: OpenAIRE