PHYSICO-CHEMICAL SENSOR

• Main Authors: ITO YOSHITAKA, KATSUBE TERUAKI, OGATA OKI
• Format: Patent
• Language: English
• Published: 07.04.1995
• Edition: 6
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PURPOSE:To realize a highly stable and highly sensitive sensing system by a novel differential configuration in a physico-chemical sensor employing a surface photovoltaic method. CONSTITUTION:In the physico-chemical sensor wherein an insulation layer 4 is provided on a semiconductor substrate 5, a detection electrode 1 is provided thereon, and the surface of detection electrode 1 or the rear of the semiconductor substrate 5 is irradiated with an intermittent light beam to generate pairs of electrons and holes in the semiconductor substrate 5 thus inducing an AC photocurrent or photovoltage on the surface of the semiconductor substrate, a differential configuration taking the difference between two signals by two intermittent optical beams having arranged characteristics is employed on substrate 5. Sensing part and reference part on the surface of the substrate are irradiated individually with two pulse lights of the same wavelength having phase shift of one half wavelength and the difference between the photocurrents for half wavelengths is determined every period.