Amorphous-Selenium-Based Three-Terminal X-Ray Detector With a Gate

A three-terminal amorphous-selenium-based photoconductive photodetector is presented where the photoconductive layer is coated on two coplanar electrodes on a glass substrate, acting as the source and drain, and a third electrode is deposited atop the photoconductor, functioning as a gate. The detector has I-V transfer characteristics that can be controlled by the gate voltage and depend on the incident radiation (in kilovolt peak), a general requirement. The advantage of this structure is its simplicity and its ability to fully control the signal by the gate voltage, which has the potential for eliminating the TFT switch in large-area direct conversion X-ray imaging.