Photoconductivity in highly tetrahedral diamondlike amorphous carbon

A photoconductive effect is observed in tetrahedral amorphous carbon (ta-C) or amorphous diamond films with a high proportion of sp3 bonding and a structure analogous to amorphous silicon. The spectral response is shown to peak at around 750–800 nm and extend into the near UV region. The maximum photoresponse coincides with the optical absorption edge. The quantum efficiency of 300 nm thick films with interdigitated electrodes is over 10% in the wavelength range 450–800 nm.