Development of Photo Sensor Using Magnetic Semiconductor

This paper describes the preparation and response to light stimulation of a magnetic semiconductor photosensor (MSP). The MSP is composed of ferrite powder, binder, solvent and a radiant flux absorbent. After the mixed magnetic semiconductor fluid is printed using a spray gun, it is sintered at 800C and its surface is covered with radiant flux absorbent. When light in the visible wavelength range is incident on the MSP, the radiant flux absorbent absorbs the radiant energy and the element temperature rises. As a result the MSP reluctance increases, so that an optical stimulus is manifested as a change in magnetic behavior, that is read out by a Hall element. MSPs can be used in photo relays, illuminance meters and photocouplers.