The optimization of diamond films as valuable engineering materials for a wide variety of applications has required the development of robust methods for their characterization. Of the many methods used, Raman microscopy is perhaps the most valuable because it provides readily distinguishable signatures of each of the different forms of carbon (e.g. diamond, graphite, buckyballs). In addition it is non-destructive, requires little or no specimen preparation, is performed in air and can produce spatially resolved maps of the different forms of carbon within a specimen. This article begins by reviewing the strengths (and some of the pitfalls) of the Raman technique for the analysis of diamond and diamond films and surveys some of the latest developments (for example, surface-enhanced Raman and ultraviolet Raman spectroscopy) which hold the promise of providing a more profound understanding of the outstanding properties of these materials. The remainder of the article is devoted to the uses of Raman spectroscopy in diamond science and technology. Topics covered include using Raman spectroscopy to assess stress, crystalline perfection, phase purity, crystallite size, point defects and doping in diamond and diamond films.

Raman spectroscopy of diamond and doped diamond.

http://www.chm.bris.ac.uk/pt/diamond/pdf/drm17-105.pdf

Raman and conductivity studies of boron-doped microcrystalline diamond, facetted nanocrystalline diamond and cauliflower diamond films

In order to produce polycrystalline oxygen-terminated boron-doped diamond (BDD) electrodes suitable for electroanalysis (i.e., widest solvent window, lowest capacitive currents, stable and reproducible current responses, and capable of demonstrating fast electron transfer) for outer sphere redox couples, the following factors must be considered. The material must contain enough boron that the electrode shows metal-like conductivity; electrical measurements demonstrate that this is achieved at [B] > 1020 B atoms cm–3. Even though BDD contains a lower density of states than a metal, it is not necessary to use extreme doping levels to achieve fast heterogeneous electron transfer (HET). An average [B] ∼ 3 × 1020 B atoms cm–3 was found to be optimal; increasing [B] results in higher capacitive values and increases the likelihood of nondiamond carbon (NDC) incorporation. Hydrogen-termination causes a semiconducting BDD electrode to behave metal-like due to the additional surface conductivity hydrogen terminatio...

M. Bernard

Papers

Non-destructive determination of the boron concentration of heavily doped metallic diamond thin films from Raman spectroscopy

Electron cyclotron resonance oxygen plasma etching of diamond