FIELD EMISSION ELEMENT

摘要

PROBLEM TO BE SOLVED: To increase the carrier concentration within a semiconductor directly participating in emission current density, and increase modulation effect of emission current by light irradiation modulation by assembling an avalanche photodiode in an electron supply mechanism of MIS structure. SOLUTION: Voltage Vd is applied to an APD-MIS diode. The polarity of the voltage is set so that a p/n+ diode reaches an avalanche operation region, and strong electric field is applied to an I layer, and a tunnel effect is generated. Anode voltage Va is set so that an emitter corresponds to saturated region operation. When light comes in through a transparent electrode from the back of an APD-FED, a doubling phenomenon of produced carrier caused by optical excitation is produced in the avalanche region of a P layer, and carrier concentration is increased. The increased carrier acts as a supply function of tunnel current caused by a tunnel effect, flowing through the I layer, and increases injection current into an M layer of the APD-MIS.