An embodiment of the invention relates to a radiation detector device including a detector substrate for direct conversion of X-ray and/or gamma quanta to electrical charge. The detector substrate includes a semiconductor material including Cadmium； a readout substrate having a readout contact； a charge collector contact for collecting an electrical charge from the detector substrate； and a connection. The connection electrically interconnects the charge collector contact and the readout contact. The connection includes a solder connection. The solder includes Bismuth, Tin and Silver.
