Methane-induced texturing of CVD diamond films and correlation with UV photoresponse

The aim of the present work was to investigate the correlation between response to UV photons and crystal orientation in diamond films. Some chemical vapor deposition diamond samples were exposed to UV radiation (4-6 eV) and the photocurrent measured applying several electric fields. The orientation of diamond films has been checked by X-ray diffraction and the resulting spectra were used to define the percentage of texture. The results of our experiments show a clear correlation between UV photoresponse and film texture, obtained by varying the methane concentration in the growth plasma. Also, less oriented polycrystalline fihns have a better response than highly (100) textured films in terms of photocurrent and signal to noise ratio.