The present invention discloses an X-ray imaging device comprising an X-ray absorber that comprises a plurality of semiconductor layers. The plurality of semiconductor layers comprise a substrate having a backside; and at least one absorption layer adapted to absorb at least one X-ray photon impinging on the at least one absorption layer that is adapted to correspondingly generate in response to the at least one impinging X-ray photon at least one electron-hole pair; and a readout unit, wherein the readout unit is operatively coupled to the X-ray absorber such to enable readout of the at least one electron-hole pair. Additional and alternative embodiments are described and claimed.