Photosensor, semiconductor device including photosensor, and light measurement method using photosensor
First Claim
1. A sensor comprising:
- a transistor including a channel including an oxide semiconductor; and
an oscillator circuit,wherein an output of the oscillator circuit is electrically connected to a gate electrode of the transistor,wherein the channel is a receiving portion, andwherein the oscillator circuit includes a light blocking layer.
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Accused Products
Abstract
An object is to provide a photosensor utilizing an oxide semiconductor in which a refreshing operation is unnecessary, a semiconductor device provided with the photosensor, and a light measurement method utilizing the photosensor. It is found that a constant gate current can be obtained by applying a gate voltage in a pulsed manner to a transistor including a channel formed using an oxide semiconductor, and this is applied to a photosensor. Since a refreshing operation of the photosensor is unnecessary, it is possible to measure the illuminance of light with small power consumption through a high-speed and easy measurement procedure. A transistor utilizing an oxide semiconductor having a relatively high mobility, a small S value, and a small off-state current can form a photosensor; therefore, a multifunction semiconductor device can be obtained through a small number of steps.
119 Citations
8 Claims
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1. A sensor comprising:
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a transistor including a channel including an oxide semiconductor; and an oscillator circuit, wherein an output of the oscillator circuit is electrically connected to a gate electrode of the transistor, wherein the channel is a receiving portion, and wherein the oscillator circuit includes a light blocking layer. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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Specification