Optical and Electrical Properties of Transparent Carbon Nanofilm Sandwiched between Transparent Alumina Determined Using a Touch Technique

Abstract

This study investigated the optical and electric properties of carbon nanofilms for capacitive application. The carbon nanofilms were sandwiched between alumina layers, and the specimens were covered with SiO2 nanofilm. Aluminum patterns were inscribed and used to determine the contact location. The optical and electrical properties of the transparent nanofilms were measured as the specimen was used as a touch panel. Light transmittance, film thickness, spacing, voltage, resistance, and electrical current were measured. Finally, an LCR meter was used to measure the inductive capacitance points. Glass was used as the substrate in this study. Carbon graphite was sputtered onto a metastable aluminum nanofilm, which was then cured. This carbon transits from an excellent conductivity (sp2 -bonded) to an insulating (sp3 -bonded). Metal can be transparent at the nanoscale, and its metastability can be sustained for a few hours. Graphite was sputtered onto aluminum nanofilm, and the carbon layer contained weak dipoles, resulting in weak capacitance. Consequently, sp3 bonding was dominant after curing. The transparency and capacitance of the samples was related to the thickness of and pattern in the aluminum layer.