A novel detector for the detection of terahertz (THz) radiation has been developed using a multilayer of graphene on low temperature grown (LTG) GaAs. This detector outperforms conventional detectors with metallic contacts. Sensitivity, dynamic range and bandwidth are significantly improved. The resulting sensitivity and dynamic range are approximately 30 times greater and the bandwidth is doubled. The transparency of the graphene electrodes, which allows visible and near-infrared light to pass through, is the key to this improvement. This allows the LTG-GaAs material to excite mobile carriers not only between the electrode fingers, but also below them. The enhanced photocurrent measured in this setup is supported by mathematical models and simulations that explain how the enhancement occurs