Radiation detection element, radiation detector and radiation detection device

A radiation detection element, comprising:

• a semiconductor part having a plate shape;
• a first electrode that is disposed on a first surface being one surface of the semiconductor part and that is configured to collect charges generated by incidence of radiation in the semiconductor part and to output a signal;
• a second electrode that is disposed on a second surface being the other surface of the semiconductor part and that is applied with voltage needed for collecting the charges;
• and
• a heavily-doped layer that is disposed at a region of the second surface excluding an edge of the semiconductor part and is doped heavier than the semiconductor part with dopants for making a type of a semiconductor equal to that of the semiconductor part, wherein
• the second electrode is doped with dopants for making a type of a semiconductor different from that of the semiconductor part and the constituent of the second electrode is a semiconductor being different in type from the semiconductor part, and
• the heavily-doped layer is on the second surface located at a position overlapped with the second electrode and is thicker than the second electrode.