The study on the behaviour of deuterated benzene detectors in the energy range from 1 to 10 MeV has been carried out. It is shown that the photon-to-neutron discrimination, attained with standard detectors, can be improved by doping the C6D6 liquid scintillator with high-Z elements. The motivation for doping the organic scintillator stems from the fact that they should increase the gamma detection efficiencies with no significant changes in the abilities to detect neutrons. The results obtained using the MCNP and EGS4 codes show that increasing the fraction of high-Z elements: (a) the energy deposited in the medium by photons increases, (b) the energy deposited by neutrons decreases and (c) the rate of detection of photon/neutron is enhanced. Owing to their low sensitivity to neutrons and the enhanced gamma detection efficiency, these detectors could be ideally used to carry out studies in mixed neutron-photon fields in the energy range considered and to assess the gamma backgrounds in noisy neutron environments.