Abstract: In this monolithic detector array, a signal processing layer is epitaxially formed directly on an active detector layer. The active detector layer is supported by a transparent substrate. The three layers are made of intrinsic semiconductors of the same conductivity type (e.g., n-type). The semiconductor forming the active layer has a smaller bandgap than the signal processing and substrate layers. A plurality of vias of opposite conductivity type (e.g, p-type) extend through the signal processing layer into the active detector layer where they form p-n junctions with the active detector layer. These p-n junctions collect charges generated by the radiation and the vias conduct these charges to the signal processing layer where gates, AC background suppression circuitry, and a charge coupled device process the photogenerated signals.