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Title: Detailed investigation of optoelectronic and microstructural properties of plasma polymerized cyclohexane thin films: Dependence on the radiofrequency power

Abstract

Optical properties of polymerized cyclohexane films deposited by radiofrequency plasma enhanced chemical vapor deposition technique at different radiofrequency powers onto glass and silicon substrates, are studied and correlated with the microstructure of the films, using a combination of atomic force microscopy, Raman and Fourier Transformer Infrared spectroscopy and optical measurements. The optical constants such as refractive index n, dielectric permittivity ε and extinction k and absorption α coefficients, are extracted from transmission and reflection spectra through the commercial software CODE. These constants lead, by using common theoretical models as Cauchy, Lorentz, Tauc and single effective oscillator, to the determination of the static refractive index n{sub s} and permittivity ε{sub s}, the plasma frequency ω{sub p}, the carrier density to effective mass ratio N/m{sub e}{sup *}, the optical conductivity σ{sub oc}, the optical band gap E{sub g} and the oscillation and dispersion energies E{sub 0} and E{sub d}, respectively. We find that n, ε{sub s}, ω{sub p}, N/m{sub e}{sup *}, E{sub d}, increase with radiofrequency power, while E{sub g} and E{sub 0} decrease in the same range of power. These results are well correlated with those obtained from atomic force microscopy, Raman and infrared measurements. They also indicate that the increasemore » of the radiofrequency power promotes the fragmentation of the precursor and increases the carbon C-sp{sup 2} hybridization proportion, which results in an improvement of the optoelectronic properties of the films.« less

Authors:
;  [1];  [2]; ; ;  [1]; ; ;  [3]
  1. Laboratoire de Physique de la Matière Condensée, Université de Picardie Jules Verne, UFR des Sciences d'Amiens, 33 rue Saint Leu, 80039 Amiens Cedex 2 (France)
  2. (Tunisia)
  3. Laboratoire de Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis (Tunisia)
Publication Date:
OSTI Identifier:
22412899
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 117; Journal Issue: 21; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION SPECTROSCOPY; ATOMIC FORCE MICROSCOPY; CARRIER DENSITY; CHEMICAL VAPOR DEPOSITION; CYCLOHEXANE; DIELECTRIC MATERIALS; EFFECTIVE MASS; GLASS; INFRARED SPECTRA; LANGMUIR FREQUENCY; MICROSTRUCTURE; OSCILLATORS; PERMITTIVITY; PLASMA; RADIOWAVE RADIATION; REFRACTIVE INDEX; SILICON; THIN FILMS

Citation Formats

Manaa, C., Bouaziz, L., Laboratoire de Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis, Lejeune, M., Zellama, K., E-mail: kacem.zellama@u-picardie.fr, Benlahsen, M., Kouki, F., Mejatty, M., and Bouchriha, H. Detailed investigation of optoelectronic and microstructural properties of plasma polymerized cyclohexane thin films: Dependence on the radiofrequency power. United States: N. p., 2015. Web. doi:10.1063/1.4921703.
Manaa, C., Bouaziz, L., Laboratoire de Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis, Lejeune, M., Zellama, K., E-mail: kacem.zellama@u-picardie.fr, Benlahsen, M., Kouki, F., Mejatty, M., & Bouchriha, H. Detailed investigation of optoelectronic and microstructural properties of plasma polymerized cyclohexane thin films: Dependence on the radiofrequency power. United States. doi:10.1063/1.4921703.
Manaa, C., Bouaziz, L., Laboratoire de Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis, Lejeune, M., Zellama, K., E-mail: kacem.zellama@u-picardie.fr, Benlahsen, M., Kouki, F., Mejatty, M., and Bouchriha, H. 2015. "Detailed investigation of optoelectronic and microstructural properties of plasma polymerized cyclohexane thin films: Dependence on the radiofrequency power". United States. doi:10.1063/1.4921703.
@article{osti_22412899,
title = {Detailed investigation of optoelectronic and microstructural properties of plasma polymerized cyclohexane thin films: Dependence on the radiofrequency power},
author = {Manaa, C. and Bouaziz, L. and Laboratoire de Matériaux Avancés et Phénomènes Quantiques, Université de Tunis El-Manar, Faculté des Sciences de Tunis, Campus universitaire El-Manar, 1068 Tunis and Lejeune, M. and Zellama, K., E-mail: kacem.zellama@u-picardie.fr and Benlahsen, M. and Kouki, F. and Mejatty, M. and Bouchriha, H.},
abstractNote = {Optical properties of polymerized cyclohexane films deposited by radiofrequency plasma enhanced chemical vapor deposition technique at different radiofrequency powers onto glass and silicon substrates, are studied and correlated with the microstructure of the films, using a combination of atomic force microscopy, Raman and Fourier Transformer Infrared spectroscopy and optical measurements. The optical constants such as refractive index n, dielectric permittivity ε and extinction k and absorption α coefficients, are extracted from transmission and reflection spectra through the commercial software CODE. These constants lead, by using common theoretical models as Cauchy, Lorentz, Tauc and single effective oscillator, to the determination of the static refractive index n{sub s} and permittivity ε{sub s}, the plasma frequency ω{sub p}, the carrier density to effective mass ratio N/m{sub e}{sup *}, the optical conductivity σ{sub oc}, the optical band gap E{sub g} and the oscillation and dispersion energies E{sub 0} and E{sub d}, respectively. We find that n, ε{sub s}, ω{sub p}, N/m{sub e}{sup *}, E{sub d}, increase with radiofrequency power, while E{sub g} and E{sub 0} decrease in the same range of power. These results are well correlated with those obtained from atomic force microscopy, Raman and infrared measurements. They also indicate that the increase of the radiofrequency power promotes the fragmentation of the precursor and increases the carbon C-sp{sup 2} hybridization proportion, which results in an improvement of the optoelectronic properties of the films.},
doi = {10.1063/1.4921703},
journal = {Journal of Applied Physics},
number = 21,
volume = 117,
place = {United States},
year = 2015,
month = 6
}
  • The electrical properties of plasma-polymerized films are summarized and compared to those of conventional polymers. Particular attention is devoted to the dielectric relaxation, dielectric breakdown, electric conductivity and photoconductivity, and their control via control of the plasma parameters.
  • A plasma-polymerized cyclohexane (PPCHex) thin film was characterized by using Fourier transform infrared spectroscopy, x-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry along with a principal component analysis (PCA). The PPCHex thin film was deposited onto a silicon substrate by using an inductively coupled plasma chemical vapor deposition method and cyclohexane as a precursor. The chemical composition of the PPCHex surface was controlled in a reproducible manner as a function of substrate bias plasma power. A PCA of the TOF-SIMS data also gave systematic insight into the surface chemical compositions and molecular cross-linking on plasma-polymerized thin films as amore » function of substrate bias plasma power. PPCHex thin film made at 100 W plasma power had the least amount of oxygen functional groups such as the C-O-H form on the surface than the one made at 10 W plasma power.« less
  • Ultrathin, uniform, pinhole-free solid polymer electrolyte films of approximately 1 {mu}m thickness were prepared by the complexation of plasma-polymerized tris(2-methoxyethoxy)vinylsilane (TMVS) with LiClO{sub 4}. The results of FT-IR, {sup 1}H NMR, and {sup 13} C NMR measurements indicate that the structure of the plasma polymer is very similar to poly (TMVS), except for the presence of a small amount of what is probably a cycle group impurity. The glass transition temperature and ionic conductivity of the solid polymer electrolyte depend on the LiClO{sub 4} content, and the variation of the ionic conductivity with temperature can be described exactly by usingmore » a {ital WLF} type of equation. Room temperature conductivities greater than 10{sup {minus} 6} S cm{sup {minus} 1} (10{sup 2}{Omega} cm{sup 2} resistance per unit area) were observed.« less
  • We investigated the surface stress change of plasma-polymerized allylamine films on 2 {mu}m thick silicon micromechanical cantilever substrates induced by ultraviolet light (UV) irradiation. Compressive surface stress was generated during the UV irradiation of the plasma-polymerized films in a dry environment, whereas tensile stress was measured in a humid environment. Fourier transform infrared spectroscopic analysis indicated two mechanisms taking place depending on the environmental conditions. These were attributed to crosslinking and oxidation reactions of the plasma polymer. UV irradiation of plasma polymerized allylamine films at defined humidity suggests a feasible method for achieving tensile and compressive surface stress patterning.
  • Several physical properties of thin plasma-polymerized films have been measured using a new fiber-optic-based technique. Films of plasma-polymerized tetrafluoroethylene (PPTFE) deposited on the end of an optical fiber form an optical cavity, the reflectivity of which is very sensitive to the film thickness. The fiber is used as an {ital in} {ital situ} monitor of the deposition rate in the plasma and, after removal from the plasma, the mechanical properties of the film can be measured. With this measurement technique the thermal expansion of the film normal to its surface as well as the swelling of the film when exposedmore » to an array of organic solvents have been determined. A significantly smaller thermal-expansion coefficient and larger degree of swelling are observed relative to bulk PTFE. X-ray photoelectron spectroscopy measurements show that the fluorocarbon chains are highly branched and have a fluorine-to-carbon ratio of 1.45. These results suggest that the plasma-polymerized films are not crystalline and are heavily cross linked.« less