At least one embodiment of the invention relates to an X-ray radiation detector, in particular for use in a CT system. In at least one embodiment, the X-ray radiation detector includes a semiconductor material used for detection, at least two ohmic contacts between the semiconductor material and a contact material, the semiconductor material and contact material each having a specific excitation energy of the charge carriers, with the excitation energy of the contact material corresponding to the excitation energy of the semiconductor material. At least one embodiment of the invention furthermore relates to a CT system in which an X-ray radiation detector is used, the X-ray radiation detector advantageously having at least two ideal ohmic contacts according to at least one embodiment of the invention.