A pyroelectric detector which includes at least one pyroelectric element consisting of a pyroelectric material sandwiched between first and second electrodes, and a semiconductor chip having a field effect transistor formed on one surface thereof and having an electrical contact for the gate electrode of the transistor formed on the surface thereof, opposite to said one surface, the gate electrode contact of the chip being secured in electrical contact to the first one of the electrodes of the pyroelectric element, the size of the chip being such that a major portion of the first electrode is not covered by the chip.
A very thin insulator having a dipole structure such as a dielectric material having ferroelectric properties and, preferably, also having thermodielectric properties, is used as the insulator insulating an electrode of an electrode pair from a semiconductor body sandwiched between said electrode pair. The utilization of the charge storage and transfer ability serves as a large scale memory device. Radiation detection and solar energy conversion systems based on establishment of an inversion layer by the bound charge of thermodielectric layer or an electret and irradiation of the semiconductor to separate the electron-hole pair and subsequent collection of minority carriers. Since there is no physical junction, the voltage is high, and can be an alternating current voltage which can be transformed. In one embodiment the dielectric material exhibiting thermodielectric properties provides the bound charge and is used in a thermal imaging system. In such system a matrix or mosaic of charged thermodielectric capacitors biased to near the Curie temperature, are exposed to a source of infrared to be detected. Such mosaic of thermodielectric capacitors is used to convert the IR image to electrical signals.
A pyroelectric sensor senses the infrared rays radiated from the human body and outputs the detected infrared rays as an electric signal. It detects the trespass of somebody on a room and is used for the prevention of crimes and the like. The pyroelectric sensor includes a substrate, an element-pair disposed on the surface of the substrate and an amplification circuit for amplifying the current signals output from the element-pair. The substrate is composed of a material having a thermal conductivity as low as not more than 0.04 cal/cm sec.degree. C. so as to prevent the heat from being released through the substrate. A hole is formed in the substrate. The amplification circuit amplifies the current signals of the element-pair, thereby dispensing with the impedance transformation which is inevitable in the prior art. Thus, the sensitivity of detection is improved and the manufacture of the sensor is facilitated.
A very thin insulator having a dipole structure such as a dielectric material having ferroelectric, pyroelectric and or thermodielectric properties, is used as the insulator insulating an electrode of an electrode pair from a semiconductor body sandwiched between said electrode pair forming a MIS structure. Radiation and solar energy conversion systems based on establishment of an inversion layer by the thermally released bound charges of a polarizable dielectric layer or an electret and irradation of the semiconductor to separate the electron-hole pairs and subsequent collection of mobile carriers. Since there is no metalurgical junction, the generated carriers are not junction limited therefore the generated voltage could be higher than in an ordinary junction solar cell and could also be, an alternating current voltage which can be transformed or rectified.
A mounting means for apparatus useful for processing infrared signals including a pyroelectric detector array with a plurality of detector elements, a plurality of electrically conductive epoxy polymer mounting means having two ends and attached at one end to the detector array to provide individual electrical contact for each of the detector elements. The apparatus further includes circuit means attached to the other end of the mounting means for processing electrical signals from the array.
A pyroelectric detector comprising a substrate, pyroelectric material distributed in a binder and applied to said substrate, and at least two electrically conductive electrodes, wherein the pyroelectric material comprises lithium tantalate consisting of single crystal particles, said lithium tantalate containing an amount of tantalum ranging from 25 to 75 mole % as tantalum pentoxide.
