A semiconductor radiation detector device comprises a conductive backside layer (102) of first conductivity type and a bulk layer (103). Opposite to the conductive backside layer (102) there are a modified internal gate layer (104) of second conductivity type, a barrier layer (105) of the first conductivity type and pixel dopings (110, 112, 506, 510, 512) of the second conductivity type. The pixel dopings are adapted to be coupled to a pixel voltage, which is defined as a potential difference to a potential of the conductive backside layer (102), and which creates potential minima inside the detector material for trapping the signal charges.