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.
Hot-electron injection EL (HEI-EL) devices have been fabricated on p-type Si substrates. Due to hot-electron injection into the ZnS : Mn emission layer through an SiO_2 insulating leyer from the Si substrate, HEI-EL devices show lower driving voltages in comparison with conventional TFEL devices. When the device was prepared on a p-layer formed by boron ion implantation of a n-type Si wafor, the driving voltage became lower and luminance became higher compared to devices constructed on a simple p-type wafer. Further it was found that the luminance was controlled by the dc bias voltage applied across the interface between p-Si and SiO_2.