Patent ID: 6528794
Filing Date: 2003-03-04
Classification: H01L

Abstract:
A radiation detecting apparatus for converting incident radiation into electric signals, comprising:a radiation sensitive semiconductor layer for generating carriers in form of electron-hole pairs in response to the incident radiation; a pair of electrodes formed on opposite surfaces of said semiconductor layer, respectively, one of said electrodes being a voltage application electrode to which a negative bias voltage is applied, the other electrode being a carrier collection electrode; a charge storing capacitor connected to said carrier collection electrode for storing charges generated by movement of the carriers in said semiconductor layer; a switching element connected to said capacitor, said switching element being turned off when the charges accumulate in said capacitor, and turned on when taking the charges out of said capacitor; and charge-to-voltage converting means for converting the charges taken out of said capacitor through said switching element into voltage signals acting as radiation detection signals; wherein said semiconductor layer is formed of one of an n-type amorphous semiconductor and an n-type polycrystal semiconductor, both being of high specific resistance, with a &mgr;&tgr; product of holes being larger than a &mgr;&tgr; product of electrons, the &mgr;&tgr; product being a product of mobility &mgr; and mean life &tgr; of the electrons and holes generated by the incident radiation; and wherein said semiconductor layer has a structure formed on a voltage application electrode side thereof for inhibiting injection of electrons, and a structure formed on a carrier collection electrode side for permitting injection of holes.