Cathodoluminescence and photoluminescence from chemical-vapor-deposited diamond

Abstract

Cathodoluminescence spectra from microwave-plasma-assisted chemical-vapor-deposited (CVD) diamond have been studied as a function of temperature at low electron energies. This investigation shows a pronounced difference between the luminescence spectra from CVD diamond films as grown and CVD diamond films annealed by rapid thermal processing at 1000 °C for one minute in an argon atmosphere. The relative intensities of the dominant features at 443 nm (2.8 eV) and 510 nm (2.4 eV) are very different for unannealed and annealed samples. We report measurements of the temperature dependence of these luminescence bands.

GE POL Diamonds: Before and After

“…With the flood gun technique, it was most clearly shown that the "green" band was either dramatically reduced or completely eliminated. A similar decrease of this CL band was reported by Yang et al (1995). This resulted in a single dominant "blue" band in the spectra for all of the samples after processing.…”

X-ray Excited Optical Luminescence from Diamond Thin Films: The Contribution of sp2- and H-Bonded Carbon to the Luminescence

“…gap semiconductors is not uncommon as the near band-edge emission can be quenched by the defect energy states in the band gap. These emissions have been observed in the PL 8,14 and CL 9,15 analyses of CVD diamond films. The C K-edge XANES spectra recorded in total electron yield (TEY), X-ray fluorescence yield (FLY), and PLY (zero order) are displayed in Figure 2b.…”

“…1,2 The photoluminescence (PL) excited by UV or visible light and cathodoluminescence (CL) excited by the electron beam from diamond thin films prepared by chemical vapor deposition (CVD) techniques have been widely studied. A sharp band at 1.68 eV [3][4][5] and several broad-band emissions at higher energies [6][7][8][9][10][11][12][13][14][15] from CVD diamond films have been reported. It is widely accepted that the sharp emission at 1.68 eV is related to defect centers involving silicon impurity in diamond.…”

“…[3][4][5] However, the origin of the broadband emissions is still not well understood. These broad-band emissions have been attributed to the phase impurities of shortrange sp 2 -bonded carbon [6][7][8][13][14][15] and hydrogen [9][10][11][12][13][14] on the surfaces of CVD diamond films. The sp 2 -bonded carbon model can partly explain the experimental results, particularly, the increase of the intensity of some broad luminescence bands with the increase in content of the sp 2 -bonded carbon in the diamond films.…”