HYDROGENATED AMORPHOUS-SILICON CRYSTALLINE SILICON DOUBLE-HETEROJUNCTION X-RAY SENSOR

With full utilization of the low-temperature process of hydrogenated a morphous silicon (a-Si) thin-him deposition and long carrier lifetime of high-purity crystalline silicon (c-Si), we have developed a new typ e of a-Si/c-Si double heterojunction X-ray sensor. The sensor has the structure of Au/p a-SiC/n NTD c-Si/n a-SilAl. High-purity NTD (neutron transmutation doping) crystalline silicon wafers were used as substra tes. The high-purity NTD crystalline silicon has a long carrier lifeti me (about 400 mu s), and the low deposition temperature of a-Si has no adverse effects on the carrier lifetime. Therefore, high photogenerat ed carrier collection efficiency and high sensitivity can be obtained. The characteristics of this kind of X-ray sensor have been examined. The linearity of the relationship between output current and X-ray int ensity was good, and the sensitivity was high.