US Patent 9202961 Imaging devices with solid-state radiation detector with improved sensitivity

A radiation detector includes a semiconductor substrate having opposing front and rear surfaces, a cathode electrode located on the front surface of the semiconductor substrate configured so as to receive radiation, and a plurality of anode electrodes formed on the rear surface of said semiconductor substrate. A work function of the cathode electrode material contacting the front surface of the semiconductor substrate is lower than a work function of the anode electrode material contacting the rear surface of the semiconductor substrate.