Contactos Eléctricos Transparentes Mediante Nanoestructuración De Películas Metálicas

Abstract

En el presente trabajo se propone un método para la fabricación de películas nanoestructuradas de Ag por evaporación al vacío en el cual se mide en tiempo real su resistividad por unidad de espesor durante el crecimiento de la misma. La incorporación de un comparador de resistencias permite un control del corte de evaporación con el cual se ha logrado repetibilidad en la producción de películas con <10 y transmitancia media del 60 % en el espectro visible. Analizamos los efectos de la nanoestructura de las películas delgadas de Ag sobre las propiedades electro-ópticas. Encontramos que la conductividad respecto al bulto puede ser menor a baja frecuencia, mientras que mayor en el rango óptico, debido a disipación de energía por la excitación de plasmones. Palabras clave: películas delgadas, nanoestructuras, conductividad, transmitancia.In this paper we propose a method for making Ag nanostructured films by evaporation under vacuum and is measured in real time the resistivity per unit thickness for the growth of the same. The incorporation of a resistance comparator provides control of evaporation cut and repeatability in the films production with <10 and average transmittance 60 % in the visible spectrum. We analyze the Ag surfaces nanostructure effects for electro-optical properties. We found that the conductivity respect to bulk can be lower at low frequency, while larger in the optical range, due to energy dissipation by plasmonic excitation

Optical and electrical properties of nanostructured metallic electrical contacts

“…We analyze light emitting devices (LED) made of porous silicon (PS) over which Ag is sputtered to form an electrical contact. We prepare the PS sample by anodizing a crystalline p-doped Si substrate with resistivity 0.5-1.0Ωcm terminated in a (100) surface, using a well known procedure: 39 We immerse the Si crystal in an electrolytic solution of hydrofluoric acid, distilled water, and ethanol in proportions 1:1:2 and we apply a current with a density of 20 mA/cm 2 for a duration of 120 s 12 to obtain a sample with an expected porosity p ≈ 80%. We discard the electrolytic solution and clean the system with an ethanol bath.…”

“…If we use a diluted solution of potassium chloride as an electrolytic contact and apply a forward current with density 16 mA/cm 2 an electroluminescent signal is produced. We measured the normalized spectral emission with an Hitachi fluorimeter F2000 with blocked excitation source 25s after turning the current on 40 . The results are displayed in Fig.…”

“…Near but above the percolation threshold, while the conductive phase is connected, there appear optical resonances at which the transmittance is suppressed due to the power dissipated as Joule heat. 12 In the present work, we employ a computationally efficient recursive formalism for the calculation of an effective dielectric response of nanostructured films when the length-scale of the inhomogeneities of the film are much smaller than the wavelength, thus neglecting retardation. 5,6,13 This non-retarded recursive method (RM) is applicable 14 to nano-textured inhomogeneities with scales up to one order of magnitude below the nominal wavelength.…”