Optical properties of transparent electrodes based on carbon nanotubes and graphene platelets

Abstract

Composite transparent electrodes based on carbon nanostructures such as multiwalled carbon nanotubes and graphene platelets were spray coated onto glass substrates and characterized by spectrophotometry and spectroscopic ellipsometry measurements. The dispersion relations of the ellipsometric angle rate, i.e. W and D versus wavelength k were measured in spectral range from 190 to 1700 nm. On the basis of these results, it was possible to estimate the value of the refractive index and extinction coefficient. Effective medium approximation model was chosen to calculate the optical constants of a mixed material. The average surface roughness and the average thickness of spray coated transparent resistive layers were also determined. The materials have a heterogeneous structure as confirmed by scanning electron microscopy and optical measurements (changes of depolarisation). From the Tauc plot it was possible to determine the energy gap. The influence of the coating process and the paint preparation on the optical properties was observed.

Spun Carbon Nanotube Fibres and Films as an Alternative to Printed Electronic Components

“…These devices would, in many cases, be impossible to produce using classical electronics as they include flexible, stretchable or transparent electrodes, antennas and displays. Additionally, these materials allow the construction of specialized components, such as structural electronic elements that can be used in both the automotive and aerospace industries as well as components for the use in the smart textiles area [5][6][7][8][9][10][11][12][13][14][15][16][17]. The solutions offered by printed electronics can improve both the functionality and reliability, while significantly decreasing the weight, size and cost of many of the systems and devices.…”

“…Materials that are particularly widely studied in this context are carbon nanotubes (CNTs) and graphene [4][5][6][7][8][9][10][11][12][13][14][15]. This is due to their light weight, high electrical and thermal conductivity, strength and low cost.…”

Printed Graphene Layer as a Base for Cell Electrostimulation—Preliminary Results

“…Currently, the possibility to differentiate stem cells from other cells, especially nerve cells, is attracting great attention within academia [ 1 , 2 , 3 ]. Nerve and glial cells form the nerve tissue; compared to other mammalian body tissues, the nerve tissue has poor regenerative properties.…”

“…Nerve and glial cells form the nerve tissue; compared to other mammalian body tissues, the nerve tissue has poor regenerative properties. Neurons are made of neural stem cells (NSCs) in the process of neurogenesis [ 1 ]; the process takes place in the brain’s neurogenic areas. Therefore, obtaining stem cells for research and cell therapy is limited.…”

“…The connective tissue—Wharton’s jelly or umbilical cord blood—appears a safe and easily accessible source of adult stem cells which can be used to differentiate into neural cells. Due to the appropriate use of mesenchymal stem cells in vitro, cells with a neural phenotype are obtainable [ 1 ]. Owning to the appropriately selected cell stimulation and its parameters in the in vitro culture, it is conceivable not only to initiate the process of cell differentiation into neural cells, but also to control their viability and proliferation [ 4 , 5 , 6 , 7 , 8 , 9 ].…”