| 摘要 |
PROBLEM TO BE SOLVED: To obtain a sensor element in which the response to incident radiation can be altered by regulating the voltage being applied to a gate electrode thereby varying the responsive area of sensor element. SOLUTION: A gate electrode 11 is applied with a positive voltage to generate a field in an active layer 13 and the sheet resistivity thereof is varied. At the same time, a negative voltage bias is applied to an upper electrode 9 which forms a reverse bias p-i-n sensor along with an intrinsic layer 16 and the active layer 13. When a sensor element 20 is subjected to incident radiation, electrons and holes are formed in the intrinsic layer 16 and the electrons separated by the field floats to flow toward the active layer 13 from which an electron flow flows to a collection electrode 15. In this regard, responsive area of the element 20 can be altered by regulating the voltage being applied to the electrode 11. When the terminal conductance of electrode 15 is kept constant and the resistance R is decreased by increasing the positive bias voltage, for example, the responsive area is enlarged. Consequently, response to the incident radiation is not limited to a predetermined region but can be altered as desired.
|
