CdTe X-ray Sensing Driven by Electron Beam From Field Emitters

In this paper, a CdTe X-ray sensing device which consists of a CdTe pin diode and a field emitter is fabricated. The CdTe pin diode was fabricated by an excimer laser doping method, which was applied to form an n-type CdTe layer. An indium thin layer was evaporated on the p-type CdTe as a dopant material, and then an n-type CdTe layer was formed by irradiating a KrF laser to the dopant layer in a high-pressure Ar ambient. The field emitter used in this experiment was sputter-induced carbon nanoneedle field emitters. A positive bias voltage of ~200 V was applied to the n-region of the CdTe diode and output currents flowing were measured in the CdTe by supplying an electron beam on the p-region of the CdTe. The electron beam current supplied from the emitter was 10 muA. The output current is shown to be proportional to the X-ray tube current which is also proportional to the X-ray intensity. Also, output current is obtained only when the electron beam is irradiated