Search results for "Metamaterials"
showing 4 items of 24 documents
Fabrication of DNA origami lattice on silicon surface for DNA-assisted lithography
2022
Metamaterials obtain new properties from having metallized nanoscale features that are often arranged in repeating patterns. In particular, there is a need to create metasurfaces with a negative refractive index. As nanoscale fabrication using conventional top-down methods can be both difficult and time-consuming, bottom-up techniques have gained growing interest. Especially, the DNA origami method can be utilized to assemble lattices with nanoscale features on 2D surfaces, which can then be metallized using DNA-assisted lithography (DALI). This thesis provides a full study of the DNA origami fishnet lattice assembly kinetics and optimization of lattice order on a silicon surface using liqu…
Purcell Enhancement and Wavelength Shift of Emitted Light by CsPbI3 Perovskite Nanocrystals Coupled to Hyperbolic Metamaterials
2020
Manipulation of the exciton emission rate in nanocrystals of lead halide perovskites (LHPs) was demonstrated by means of coupling of excitons with a hyperbolic metamaterial (HMM) consisting of alternating thin metal (Ag) and dielectric (LiF) layers. Such a coupling is found to induce an increase of the exciton radiative recombination rate by more than a factor of three due to the Purcell effect when the distance between the quantum emitter and HMM is nominally as small as 10 nm, which coincides well with the results of our theoretical analysis. Besides, an effect of the coupling-induced long wavelength shift of the exciton emission spectrum is detected and modeled. These results can be of i…
Design of anisotropic nanostructures for light control
2018
El rápido avance en métodos de micro- y nanofabricación, tanto teórica como experimentalmente, han hecho posible a día de hoy que podamos controlar el flujo de luz con una precisión sin precedentes. Los metamateriales y las metasuperficies son nanoestructuras compuestas a partir de celdas unidad dise˜nadas, de forma que permitan manipular la luz con una respuesta estipulada. Como resultado de esto, los metamateriales han proporcinoado un gran número de posibles aplicaciones nuevas que antes eran inconcebibles. En esta Tesis Doctoral nos hemos centrado en el uso de estos metamateriales excepcionales para conseguir, específicamente, partículas indetectables y también para controlar el modelad…
Experimental Observation of a Large Low-Frequency Band Gap in a Polymer Waveguide
2018
The quest for large and low-frequency band gaps is one of the principal objectives pursued in a number of engineering applications, ranging from noise absorption to vibration control, and to seismic wave abatement. For this purpose, a plethora of complex architectures (including multiphase materials) and multiphysics approaches have been proposed in the past, often involving difficulties in their practical realization. To address the issue of proposing a material design that enables large band gaps using a simple configuration, in this study we propose an easy-to-manufacture design able to open large, low-frequency complete Lamb band gaps exploiting a suitable arrangement of masses and stif…