Novel Photonic Architectures by Nanoimprinting Unconventional Materials
September 21st, 2018 AGUSTÍN MIHI

Nanostructured dielectric and metallic photonic architectures can concentrate the electric field through resonances, increase the light optical path by strong diffraction and exhibit many other interesting optical phenomena that cannot be achieved with traditional lenses and mirrors. The use of these structures within actual devices will be most beneficial for enhanced light absorption in thin solar cells, photodetectors and to develop new sensors and light emitters. However, emerging optoelectronic devices rely on large area and low cost fabrication routes such as roll to roll or solution processing, to cut manufacturing costs and increase the production throughput. If the exciting properties exhibited photonic structures are to be implemented in these devices then, they too have to be processed in a similar fashion as the devices they intend to improve.

In this presentation, I will show how we use soft nanoimprinting lithography to mold unconventional materials such as resists, polymers, cellulose or metal colloids to fabricate a variety of photonic architectures exhibiting exciting optical properties with tremendous applications as inexpensive disposable photonic components and sensors. In addition, I will present a metasurface capable of sustaining a wide variety of photonic resonant modes going from strong interference effects to Mie and Bragg modes. The interplay between these resonances results in a broadband enhancement in the optical absorption of thin films of germanium with thicknesses below 100 nm from VIS until NIR frequencies. Such a broadband enhancement in Ge thin films has tremendous implications in many optoelectronic devices such as solar cells or photodetectors.

Seminar, September 21st, 2018, 15:00. Seminar Room