| 摘要 |
PURPOSE:To provide a sensor which can be easily made to be a multisensor, easily machined, economical and easily handled by forming an insulating layer on a semiconductor substrate, arranging a gas sensing membrane, a reference electrode, and a functional electrode on the upper part, and covering them with a conductor. CONSTITUTION:An insulating layer 4 is formed on a semiconductor substrate 5 and a gas sensing membrane, a reference electrode, and a functional electrode 2 are put on it, and a conductor 1 is provided as to cover both sides of the gas sensing membrane. As the conductor 1, a solid electrolyte is used. When continuous light 6 with energy as high as the forbidden band energy or higher is radiated locally to the semiconductor substrate 5 from the back side, photocarriers which are pairs of electrons and positive holes are generated in the interface of the insulating layer 4 and the semiconductor 5. When d. c. current bias voltage is applied to the reference electrode 3, a. c. photocurrent shows a current-voltage characteristic curve having a certain maximum peak based on the bias voltage. Since the characteristic curve is shifted corresponding to the gas concentration, the resulting body can be used as a gas sensor by examining the a. c. surfacial photovoltage generated by the photocarriers and the bias voltage dependence of the current. |
