A 128 pixel uniphase resistive-gate GaAs charge-coupled device was fabricated at the TRI University Meson Facility to study its optical absorption properties under monochromatic illumination in the visible and infrared range. It was found that when the incident light energy exceeded that of the band gap, there was a progressive reduction in the charge collection efficiency. This was attributed to a carrier recombination effect at the cermet-GaAs interface. A simple recombination model was proposed to explain the observation. A comparison between theory and measurement suggested a match between the two would require a minority carrier lifetime on the order of nanoseconds and an interface recombination velocity in the neighborhood of 10(7-8) cm/s, Such a high recombination velocity suggested a surface state density as high as the density of the surface atoms. Extrinsic absorption measurement indicated the presence of additional carrier generation in the wavelength range between 1.3 and 2.0 mu m.