We present InP photodiodes fabricated on GaP substrate with unique drift dominated design, which can build an electric field throughout the active region by varying the doping concentration. The InP/GaP photodiodes have been grown, processed and characterized. The excellent spectral response, higher than 75% internal quantum efficiency in UV and visible range, demonstrates the robustness of our drift dominated devices and superior performance with even relatively low quality material. (C) 2004 Elsevier Ltd. All rights reserved.