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Nanocrystalline Diamond Films (nanocrystalline + diamond_film)
Selected AbstractsOxygen-Terminated Nanocrystalline Diamond Film as an Efficient Anode in PhotovoltaicsADVANCED FUNCTIONAL MATERIALS, Issue 8 2010Candy Haley Yi Xuan Lim Abstract The potential of using p-doped nanocrystalline diamond as the anode for organic solar cells, because of its outstanding photostability and well-matched energetics with organic dyes, is demonstrated. The interface dipole and open-circuit potential can be tuned by varying the surface termination on diamond. Oxygenated nanocrystalline diamond (O-NCD) exhibits the best photocurrent conversion among all the surface-treated electrodes studied in this work because of its large open-circuit potential. The good energy alignment of the valence band of O-NCD with the HOMO of poly(3-hexylthiophene), as well as its p-doped characteristics, suggest that O-NCD can replace the hole transport layer, such as PEDOT:PSS, needed for efficient performance on indium tin oxide (ITO) electrodes. If the sheet resistance and optical transparency on NCD can be further optimized, chemical-vapor-deposited diamond electrodes may offer a viable alternative to ITO and fluorinated tin oxide (FTO). [source] Polymerization in Nanocrystalline Diamond Films by Oxygen IncorporationPLASMA PROCESSES AND POLYMERS, Issue 9 2006Kungen Teii Abstract Summary: Structure and resistivity of nanocrystalline diamond films deposited using microwave Ar-rich/O2/CH4 plasmas have been examined as a function of the O2/CH4 ratio from 0 to 0.53. Addition of O2 to Ar-rich/CH4 plasmas likely reduced the density of C2 radicals due to loss reactions of O atoms with CH4 and CHx radicals. The Raman peak of diamond at 1,332 cm,1 was overlapped by the D peak of sp2 -bonded, disordered carbon and its intensity was a little enhanced by the O2 addition, while the average size of sp2 -bonded carbon clusters in nondiamond phases was increased. Oxygen was incorporated into the films in forms of CO bonds, which bridged the carbon clusters themselves, and formed polymer-like, large-unit structures. The resistivity of the films was drastically increased from the order of 10,4 up to 104 ,,·,m with a small O2 addition (1.2 vol.-% in total pressure), providing novel sensor and storage applications based on oxygen incorporation and desorption. Decomposition of a Raman spectrum showing the diamond, D and G modes of amorphous carbon, and trans -polyacetylene peaks. The insert represents a typical SEM image showing a film surface. [source] Surface Science Contribution to the BEN Control on Si(100) and 3C-SiC(100): Towards Ultrathin Nanocrystalline Diamond Films,CHEMICAL VAPOR DEPOSITION, Issue 7-8 2008Jean-Charles Arnault Abstract Deposition of thin and smooth nanocrystalline diamond films requires a high degree of control of the nucleation stage. The nature of the interface between diamond film and substrate is also important for some applications. The successive steps of the bias-enhanced nucleation (BEN) process are studied in-situ on Si(100) and 3C-SiC(100) using electron spectroscopies. Thin nanodiamond films (80,900,nm) have been achieved on Si(100). The formation of a thin covering SiC layer (2,3,nm) during the plasma exposure for parameters stabilization (PEPS) step leads us to study the plasma/surface interactions on 3C-SiC(100) surfaces. The C-terminated 3C-SiC(100) demonstrates a large inertia under microwave plasma (MP)CVD conditions. An enhancement of diamond nucleation on this surface is observed. Moreover, surface analysis reveals very little damage after BEN on 3C-SiC surfaces. [source] Diamond Growth on a Si Substrate With Ceramic InterlayersJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 5 2007Y. S. Li Deposition of diamond films on Si substrates precoated with a series of ceramic intermediate layers was examined. The interlayers containing SiC, SiNx, SiCN, TiSiN, and TiAlSiN were prepared by a liquid injection plasma-enhanced chemical vapor deposition (PECVD) method using alkoxide solution precursors. The subsequent diamond synthesis on these coatings was carried out by microwave plasma-assisted CVD (MPCVD) using a H2,1%CH4 mixture. A higher nucleation density of diamond was obtained on these intermediate layers than on the as-polished Si wafer, along with a nonuniform surface distribution of diamond. Diamond powder scratching pretreatment of these interlayers enhanced the nucleation density and promoted the formation of fully uniform diamond films. Particularly, nanocrystalline diamond films were directly generated on TiSiN and TiAlSiN layers under an identical deposition condition that had favored the formation of microcrystalline diamond films on Si wafers and the Si(C,N) interlayers. The mechanism for this difference is attributed primarily to a higher amount of residual amorphous carbon in TiSiN and TiAlSiN layers than that inside Si(C,N) layers. [source] Growth and properties of nanocrystalline diamond filmsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 13 2006Oliver A. Williams Abstract The aim of this paper is to summarise recent progress in the growth of small grain-sized Chemical Vapor Deposition (CVD) diamond often called nanocrystalline diamond, i.e., diamond with grains typically smaller than 500 nm. Nanocrystalline (NCD) and Ultrananocrystalline diamond (UNCD) films are new materials offering interesting applications to nanobioelectronics and electrochemistry. However NCD and UNCD thin films comprise of entirely different structures which is highlighted here in this paper. We discuss in detail the main differences in Raman spectra, optical properties and electrical transport properties. Finally we present a simple model of the conductivity mechanism in nitrogenated UNCD (N-UNCD) and boron doped NCD (B-NCD) films, and show the possibility of achieving the superconductive transition in B-NCD films. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Role of polymers in CVD growth of nanocrystalline diamond films on foreign substratesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 11-12 2009A. Kromka Abstract Spin coating of PVA polymer with fine grained diamond powder is used as the nucleation treatment for achieving growth of nanocrystalline diamond (NCD) thin films. The growth is realized by standard microwave plasma chemical vapor deposition (CVD). The morphology and character of deposited NCD film is strongly related to the growth temperature. The low temperature process (430°C) results in a growth of well-faceted continuous films. The high temperature process (830,°C) results in voids and openings in the layer. Addition of PVA as the interlayer between the substrate and the seeding polymer composite leads to more openings. The effect is the most pronounced at 830,°C. This is assigned to thermal instability of PVA and oxygen chemistry present in the early beginning of the CVD growth. An optimized seeding process based on the polymer composite procedure at low substrate temperature and low PVA amount allows the diamond growth on extremely soft substrates. [source] Polymerization in Nanocrystalline Diamond Films by Oxygen IncorporationPLASMA PROCESSES AND POLYMERS, Issue 9 2006Kungen Teii Abstract Summary: Structure and resistivity of nanocrystalline diamond films deposited using microwave Ar-rich/O2/CH4 plasmas have been examined as a function of the O2/CH4 ratio from 0 to 0.53. Addition of O2 to Ar-rich/CH4 plasmas likely reduced the density of C2 radicals due to loss reactions of O atoms with CH4 and CHx radicals. The Raman peak of diamond at 1,332 cm,1 was overlapped by the D peak of sp2 -bonded, disordered carbon and its intensity was a little enhanced by the O2 addition, while the average size of sp2 -bonded carbon clusters in nondiamond phases was increased. Oxygen was incorporated into the films in forms of CO bonds, which bridged the carbon clusters themselves, and formed polymer-like, large-unit structures. The resistivity of the films was drastically increased from the order of 10,4 up to 104 ,,·,m with a small O2 addition (1.2 vol.-% in total pressure), providing novel sensor and storage applications based on oxygen incorporation and desorption. Decomposition of a Raman spectrum showing the diamond, D and G modes of amorphous carbon, and trans -polyacetylene peaks. The insert represents a typical SEM image showing a film surface. [source] Surface Science Contribution to the BEN Control on Si(100) and 3C-SiC(100): Towards Ultrathin Nanocrystalline Diamond Films,CHEMICAL VAPOR DEPOSITION, Issue 7-8 2008Jean-Charles Arnault Abstract Deposition of thin and smooth nanocrystalline diamond films requires a high degree of control of the nucleation stage. The nature of the interface between diamond film and substrate is also important for some applications. The successive steps of the bias-enhanced nucleation (BEN) process are studied in-situ on Si(100) and 3C-SiC(100) using electron spectroscopies. Thin nanodiamond films (80,900,nm) have been achieved on Si(100). The formation of a thin covering SiC layer (2,3,nm) during the plasma exposure for parameters stabilization (PEPS) step leads us to study the plasma/surface interactions on 3C-SiC(100) surfaces. The C-terminated 3C-SiC(100) demonstrates a large inertia under microwave plasma (MP)CVD conditions. An enhancement of diamond nucleation on this surface is observed. Moreover, surface analysis reveals very little damage after BEN on 3C-SiC surfaces. [source] | |||||||||||||