Abstract
A new electron-emission-type infrared light sensor, which uses the principle of electron emission from a Pb(Zr,Ti)O3 (PZT) thin plate, has been proposed. However, the electron supply route to the emission plane is not yet well understood. As pulsed infrared light was irradiated onto the sensor, the emission current increased rapidly and decreased slowly. The emission current peak value did not change during the continuous detection operation. When the infrared light is shielded, electron emission stops, the temperature of the PZT thin plate returns to the initial state, and an electric field appears due to spontaneous polarization. It is assumed that electrons are supplied through the PZT thin plate from the back-surface electrode to the emission plane via this electric field. In the pulsed infrared light irradiation experiment, we could recognize that the emission current peak value does not depend on the light shielding time. An electron supply model from the back-surface electrode through the PZT thin plate during a detection operation is proposed. In a quasi steady or thermal equilibrium state, the electron supply to the emission plane of the PZT thin plate is sufficient for a detection operation under ordinary irradiation conditions. Therefore, the proposed sensor is viable for use as an infrared sensor or imager under ordinary infrared light irradiation.