Thin nanodiamond membranes and their microstructural, optical and photoelectrical properties

Abstract

We have grown variety of thin nanocrystalline diamond thin layers on silicon substrates with thicknesses ranging from 100 to 2000 nm. Using a bias enhanced nucleation for nucleation density over 10 10 cm -2 and changing the deposition conditions and/or using argon dilution we have obtained nanodiamond layers of different structural properties. The nucleation process and growth was monitored with Scanning Electron Microscopy (SEM); cross-section SEM and micro-Raman measurements were used to access the nanodiamond microstructure. Surface topography was followed by SEM and Atomic Force Microscopy. Windows were opened in the silicon substrate to get self-supporting diamond membrane. Diamond membranes are very smooth, homogeneous and transparent from UV to IR. Fourier Transform Photocurrent Spectroscopy has been used to access main electronic defects in the gap of this material. New defects were observed with photoionization energy of 0.37 and 0.40 eV.

Application of pyrolytic graphite modified with nano-diamond/graphite film for simultaneous voltammetric determination of epinephrine and uric acid in the presence of ascorbic acid

“…Observation of a slope of −66 mV per pH unit indicated that equal numbers of electrons and protons are involved in the electro-oxidation of EN on the surface of NDG/PGE. These results are in a good agreement with an accepted mechanism for EN oxidation [21]. A similar negative shift in the peak potential with increasing the pH of the buffer solution was observed for UA.…”

“…The studies demonstrated that NDs are biocompatible and non-toxic, and can be used for in vivo analysis. NDs possess chemically inert cores with very high surface area, and have smooth surface with excellent homogeneous mechanical and thermal properties [20,21].…”

Formation of Continuous Nanocrystalline Diamond Layers on Glass and Silicon at Low Temperatures

“…The CVD was achieved at a constant methane concentration (1% CH 4 in H 2 ) and under a total gas pressure of 30 mbar. Our previous work has shown that using an ellipsoidal reactor, running plasma under low pressures (30 mbar and lower) results in a growth of NCD with a grain size ranging from 30 to 100 nm [30]. The substrate temperature was controlled via a variable substrate holder consisting of dummy openings in the bottom part, and was kept in the range 370-410 8C (as measured by the two-color pyrometer working at wavelengths of 2.13 and 2.35 mm, Williamson-type).…”

Spectroscopy of thin nanodiamond layers and membranes

“…Si wafers and 15 · 15 mm Si plates were used. Nucleation (bias enhanced nucleation) and deposition details were presented elsewhere [2]. Nanodiamond films were also grown on alkali free glass such as Corning 7059 and Schott AF45 (1 · 1 in.…”