Probing the microstructure and electrochemical reactivity of boron-doped diamond thin-film electrodes with Raman microprobe spectroscopy and electrogenerated chemiluminescence imaging analysis

Boron-doped (greater than or equal to 10(19) B/cm(3)) diamond thin films sh ow great promise as electrode materials, particularly in the field of elect roanalysis. Some of the basic macroscopic electrochemical properties have b een identified, but many aspects of the structure-reactivity relationship o f these materials remain incompletely elucidated. Further characterization of these materials at the microscopic level is needed in order to understan d what factors influence reactivity. We report herein on the characterizati on of boron-doped diamond thin-film electrodes by Raman microprobe spectros copy and electrogenerated chemiluminescence (ECL) imaging analysis. Raman s pectroscopy was used to probe the spatial variations in the film microstruc ture, doping level, non-diamond carbon impurity content and optical propert ies over a 20 x 20 mu m(2) region. Spectra were collected from an area of a pproximately 0.4 mu m(2). ECL imaging analysis using the luminol/H2O2 chemi cal system was employed to assess the uniformity of electrode activity over a 570 x 380 mu m(2) region at a linear resolution of approx. 2.2 mu m.