Phil J. Martin

Bio: Phil J. Martin is an academic researcher from Commonwealth Scientific and Industrial Research Organisation. The author has contributed to research in topics: Thin film & Amorphous solid. The author has an hindex of 40, co-authored 129 publications receiving 6126 citations.

EELS analysis of vacuum arc-deposited diamond-like films

Abstract: Electron energy-loss spectroscopy measurements have been made on amorphous diamond-like carbon films produced by condensing the plasma stream from a filtered vacuum arc. The results are compared with spectra from diamond, graphitized carbon and amorphous carbon. Although the energy-loss spectra reveal the presence of a small quantity of sp2-bonded material in the diamond-like film, the high plasmon frequency and shape of the K-edge show that the material is essentially an amorphous form of diamond. The fraction of sp2- bonded carbon was quantified and found to be of the order of 15%. It was not possible to determine if the sp2 carbon was on the surface or throughout the bulk.

Ion-based methods for optical thin film deposition

Abstract: The optical properties of the dielectric oxide films SiO2, Al2O3, TiO2, ZrO2, CeO2 and Ta2O5 produced by ion-based techniques have been reviewed. The influence of ion bombardment during deposition is discussed in some detail and the various production techniques are described. Recent results on the deposition and properties of diamond-like carbon films are also reviewed. Finally, some examples of the practical applications of high quality dielectric oxide films are given.

Ion-beam-assisted deposition of thin films.

Abstract: Some effects on the properties of electron-beam evaporated thin films produced by ion bombardment of the growing film are reported. Substantial increases in the packing densities of SiO2 , TiO2 , and ZrO2 films have been produced as measured by the reduction in the adsorption of moisture when the films are exposed to a humid atmosphere. In a ZrO2-SiO2 multilayer interference filter, changes in the wavelength of the peak transmittance on exposure to the atmosphere have been reduced from 8 nm for films deposited without ion bombardment to <1 nm for ion-beam-assisted films.

Modification of the optical and structural properties of dielectric ZrO2 films by ion‐assisted deposition

Abstract: Low‐energy bombardment by argon and oxygen ions has been used in the deposition of thin dielectric films of ZrO2. The film packing density has been improved from 0.83 to unity with a corresponding increase in the refractive index from 1.84 to 2.19. The highest stable refractive index measured was 2.23 for oxygen ion‐assisted deposition of ZrO2 on a substrate heated to 300 °C. Ion bombardment during condensation of evaporated ZrO2 on a room temperature substrate results in crystallization into the cubic phase which is consistent with previous studies of ion impact crystallization by thermal‐spike processes. At elevated substrate temperatures the monoclinic phase is also present.

Carbon-based Supercapacitors Produced by Activation of Graphene

Abstract: Supercapacitors, also called ultracapacitors or electrochemical capacitors, store electrical charge on high-surface-area conducting materials. Their widespread use is limited by their low energy storage density and relatively high effective series resistance. Using chemical activation of exfoliated graphite oxide, we synthesized a porous carbon with a Brunauer-Emmett-Teller surface area of up to 3100 square meters per gram, a high electrical conductivity, and a low oxygen and hydrogen content. This sp 2 -bonded carbon has a continuous three-dimensional network of highly curved, atom-thick walls that form primarily 0.6- to 5-nanometer-width pores. Two-electrode supercapacitor cells constructed with this carbon yielded high values of gravimetric capacitance and energy density with organic and ionic liquid electrolytes. The processes used to make this carbon are readily scalable to industrial levels.

Diamond-like amorphous carbon

Abstract: Diamond-like carbon (DLC) is a metastable form of amorphous carbon with significant sp3 bonding. DLC is a semiconductor with a high mechanical hardness, chemical inertness, and optical transparency. This review will describe the deposition methods, deposition mechanisms, characterisation methods, electronic structure, gap states, defects, doping, luminescence, field emission, mechanical properties and some applications of DLCs. The films have widespread applications as protective coatings in areas, such as magnetic storage disks, optical windows and micro-electromechanical devices (MEMs).

Novel Carbon-Doped TiO2 Nanotube Arrays with High Aspect Ratios for Efficient Solar Water Splitting

Abstract: The photocatalytic splitting of water into hydrogen and oxygen using solar light is a potentially clean and renewable source for hydrogen fuel.1,2 There has been extensive investigation into metal-oxide semiconductors such as TiO2, WO3, and Fe2O3, which can be used as photoanodes in thin-film form.3-5 Of the materials being developed for photoanodes, TiO2 remains one of the most promising because of its low cost, chemical inertness, and photostability.6 However, the widespread technological use of TiO2 is hindered by its low utilization of solar energy in the visible region. In this study, we report the preparation of vertically grown carbon-doped TiO2 (TiO2-xCx) nanotube arrays with high aspect ratios for maximizing the photocleavage of water under white-light irradiation. The synthesized TiO2-xCx nanotube arrays showed much higher photocurrent densities and more efficient water splitting under visible-light illumination (> 420 nm) than pure TiO2 nanotube arrays. The total photocurrent was more than 20 t...