Photorefractive and Photoconductive Features of the Nanostructured Materials

Abstract

Photoconductive and photorefractive characteristics of fullerene- and nanotubes-doped organic thin films based on conjugated organics, such as polyimide, polyaniline, pyridine, etc. have been studied. In addition, the liquid crystal mesophase with nanoobjects has been investigated. The increase of the charge carrier mobility of nanosensitized organics has been established. The nonlinear refraction and cubic nonlinearity have been investigated at wavelength of 532 nm via four-wave mixing technique using Raman-Nath diffraction regime. The thin holographic grating has been written at the spatial frequencies placed in the range of 90-150 mm-1. The energy density has been chosen in the range of 0.1-0.9 J × cm -2. The correlation between photoconductive and nonlinear optical parameters has been revealed. The nanostructured materials can be proposed for different area of nano- and microelectronic applications.

Nanostructured materials and their optical features

“…In the previous studies 5, 6,9 we have shown the formation of barrier-free charge transfer pathways, increased dipole moment, and increased specific (per unit volume) local polarizability in some organic matrices doped with fullerenes, carbon nanotubes and quantum dots, where the formation of intermolecular complexes predominated over the intramolecular donor-acceptor interaction. It is necessary to take into account that the charge transfer between matrix organic molecule donor fragment and nanasensitizers can be organized due to their high electron affinity energy (for example, electron affinity energy is close to 2 eV for shungites 10 , to 2.65 eV for fullerenes 5,8 and to 3.8-4.2 eV for quantum dots 11 ) that is more than the ones for intramolecular acceptor fragments (for example, electron affinity energy of COANP acceptor fragment is close to 0.54 eV 12 and to 1.14-1.4 eV for polyimide one 13 ).…”

“…The obtained products can be considered as new materials for photonics application in a broad spectral range. This study permits to define also different areas of applications of these materials doped with nanoobjects [1][2][3][4][5][6] . It should be remarked that the main reason to use the fullerenes, shungites, and quantum dots is connected with their unique energy levels and high value of electron affinity energy.…”

Influence of the Nanostructures on the Surface and Bulk Physical Properties of Materials

“…[13]. They were, respectively: ∼ 10 It should be mentioned that nonlinear optical parameters of nanoobjects-doped structures are larger than those obtained for traditional nonlinear inorganic systems and for pure organics.…”

Advanced Optical Materials Modified with Carbon Nano‐Objects

“…The possible mechanism to increase the laser-induced change in the refractive index, nonlinear refractive index and cubic nonlinearity has been explained in the papers [8,9,[13][14][15]. The possible mechanism to increase the laser-induced change in the refractive index, nonlinear refractive index and cubic nonlinearity has been explained in the papers [8,9,[13][14][15].…”

“…It is well known that promising nano-objects such as fullerenes, carbon nanotubes (CNTs), quantum dots (QDs), shungites, and graphenes are found to permit different areas of applications of these nano-objects [1][2][3][4][5][6][7][8][9]. The general view of some of the nano-objects indicated above is shown in Figure 7.1.…”