The CdS/CdTe heterojunction devices have been fabricated for the first time by RF sputter deposition and used as X-ray imaging sensor. The sputter-deposited CdS/CdTe heterojunction sensor showed a good diode characteristic, and high X-ray sensitivity. As an application of this sensor, a one inch X-ray vidicon (imaging pick-up tube) with photoconductive target consisting of CdS/CdTe heterojunction have been developed. It was observed that the X-ray signal current was about 130 nA/cm^2 for 13 R/min, is higher than 60 nA/cm^2 of our conventional PbO X-ray target.
