Invented by Edward Hartley Sargent, Rajsapan Jain, Igor Constantin Ivanov, Michael R. Malone, Michael Charles Brading, Hui Tian, Pierre Henri Rene Della Nave, Jess Jan Young Lee, InVisage Technologies Inc
A pinned photodiode is a type of photodetector that is commonly used in digital imaging applications such as digital cameras, medical imaging, and industrial inspection. It is a type of photodiode that has a layer of optically-sensitive material, such as amorphous silicon, deposited on top of a silicon diode. The optically-sensitive layer absorbs photons and generates electron-hole pairs, which are then collected by the silicon diode.
The advantage of a pinned photodiode over other types of photodiodes is its ability to reduce dark current, which is the current that flows through a photodiode even when there is no light present. This is achieved by applying a voltage to the optically-sensitive layer, which creates a depletion region that separates the electron-hole pairs and reduces the dark current.
The market for pinned photodiodes is expected to grow significantly in the coming years, driven by the increasing demand for digital imaging applications in various industries. The medical industry, in particular, is expected to be a major driver of growth, with the increasing use of medical imaging technologies such as X-ray, CT scans, and MRI.
In addition, the automotive industry is also expected to be a major market for pinned photodiodes, with the increasing demand for advanced driver assistance systems (ADAS) and autonomous vehicles. Pinned photodiodes are used in ADAS systems to detect obstacles and other vehicles, and in autonomous vehicles for object detection and navigation.
The aerospace industry is also expected to be a significant market for pinned photodiodes, with the increasing use of unmanned aerial vehicles (UAVs) and satellites. Pinned photodiodes are used in UAVs for obstacle detection and navigation, and in satellites for remote sensing and imaging.
In conclusion, the market for pinned photodiodes formed by an optically-sensitive layer and a silicon diode is expected to grow significantly in the coming years, driven by the increasing demand for digital imaging applications in various industries. The medical, automotive, and aerospace industries are expected to be major drivers of growth, with the increasing use of medical imaging technologies, ADAS systems, autonomous vehicles, UAVs, and satellites.
The InVisage Technologies Inc invention works as follows
In different embodiments, a photodetector comprises a semiconductor substrate as well as a plurality pixel regions. Each of the plurality pixel regions includes an optically sensitive layer that is placed over the semiconductor substrate. Each of the plurality pixel regions is covered by a pixel circuit. Each pixel circuit contains a pinned fotodiode and a charge storage. A read out circuit is also included for each of the plurality of pixel regions. To form the pinned photographde, the optically sensitive layer communicates with a section of a silicon diode. The potential difference between two electrodes communicating with the optically sensitive layers associated with a region of pixels exhibits a time-dependent bias. A biasing occurring during a first film reset period is different than a biasing occurring during a second integration period.
Background for Photodetector consisting of a pinned photodiode formed by an optically-sensitive layer and a Silicon diode.
Example embodiments use a variety of pixels to detect images. Photosensitive material may be used as a pixel element. The signal may be detected by the image sensor in each of the pixels regions. It can vary depending on the intensity of the light incident on the photosensitive materials. One example embodiment of the photosensitive material is a continuous layer of interconnected nanoparticles. An electrode is used to apply a bias over volumes of light-sensing films that are pixels. The physical location of the electrodes, geometry of the film relative to these electrodes and the biasing of these electrodes can all determine the volume of light-sensing material from which an electrode collects the most electrical current.
Pixel circuitry integrates a signal in the charge store over a time period for each pixel area. The circuit stores an electric signal proportional to the amount of light that is incident on the optically-sensitive layer during the integration period. The electrical signal can be then read from the pixel circuitry to create a digital image that corresponds to the light incident on each pixel element. In some embodiments, the pixel circuitry can be built on an integrated circuit device beneath the photosensitive material. To form an image sensor, a nanocrystal-photosensitive material can be layered on top of a CMOS device. The electrodes may have metal contact layers that are connected to the CMOS integrated Circuit. This will provide a bias across the pixel areas. U.S. patent application Ser. No. No. No. No. April. 18, 2008; Ser. No. No. Mar. 18, 2011; Ser. No. No. Mar. 18th of March 2011; and, Ser. No. No. 13/099.903, entitled “Devices, Methods for High Resolution Image, and Video Capture”,? Additional descriptions of optoelectronic systems and materials were filed May 3, 2011. These additional descriptions may be used in conjunction with example embodiments. They are herein incorporated by reference in their entirety. This is an example embodiment. Other embodiments could use different photodetectors or photosensitive materials. Embodiments may, for example, use silicon or Gallium Arsenide photodetectors (GaAs).
Embodiments” include a photodetector consisting of a semiconductor substrate, a plurality pixel regions, each region comprising an optically sensive layer over the substrate, a circuit for each region comprising a pin photodiode, a charge store, and a read-out circuit for each region. The optically sensitive layers are in direct electrical communication to a portion the silicon diode in order to form a diode. In this case, the dark signal it displayed before the higher-than-100-lux lighting.
Embodiments” include a photodetector consisting of a semiconductor substrate at a first electric potential; a plurality pixel regions each comprising an optically responsive layer over the substrate; an electrode (pixel electrode), in electrical communication to the optically sensive layer and biased towards a second voltage potential; and a second electrode (“common electrode”) in electrical connection with the optically sensible layer bias to a third potential. The dark signal in the ensuing frames returns within 10% of the value of the dark signal it displayed before the illumination at least 100-lux illumination.
Embodiments” include a photodetector consisting of a semiconductor substrate, a plurality pixel regions and an optically-sensitive layer over each pixel; a first interval known as reset period; an interval known as integration period; and a third interval known as readout period. The common electrode is set at a low voltage during integration period and a higher voltage during readout period. A dark signal in the following frame returns within 10% of the value it displayed before the illumination with greater than-than-100-lux.
Embodiments include an image sensor comprising a substrate; an array of transistors, diodes, and interconnect collectively known as the read-out integrated circuit; a corresponding array of top metal; a continuously-connected semiconductor layer covering the imaging array, where the top metal and its electrical potential profile determine the direction of photocurrent flow within, and collection from, the continuously-connected semiconductor layer, wherein, following illumination of at least one pixel with an intensity greater than 100 lux, the dark signal in the ensuing frame returns within 10% to the value of dark signal it exhibited prior to the greater-than-100-lux illumination.
Embodiments include an image sensor comprising a substrate; an array of transistors, diodes, and interconnect collectively known as the read-out integrated circuit; a corresponding array of top metal; a continuously-connected semiconductor layer covering the imaging array, where the top metal and its electrical potential profile define the regions of the continuously-connected semiconductor from which photocurrent is collected, wherein, following illumination of at least one pixel with an intensity greater than 100 lux, the dark signal in the ensuing frame returns within 10% to the value of dark signal it exhibited prior to the greater-than-100-lux illumination.
Embodiments” include an integrated circuit, at least two optically-sensitive layers, a first and second optically-sensitive layers, the first layer covering at least a portion and the second layer covering the second optically-sensitive layer; a plurality electrodes, each electrode including a first electrode and a second electrode, and circuitry coupled with the integrated circuit, which outputs signals from the optically-sensitive layers. The signals correspond to light absorbed and are returned within 10% of the value it displayed before the higher-than-100-lux lighting
Embodiments” include an image sensor that comprises a semiconductor substrate and a plurality pixel regions. Each pixel area includes an optically-sensitive layer on top of the substrate. The optically-sensitive layer is positioned to receive light. A pixel circuit for each region of pixels contains a charge storage circuit and an electrical communication circuit with the optically-sensitive layer. Additionally, conductive material is placed between the respective charge stores and the optically-sensitive layer of each pixel. In this case, the dark signal it displayed before the illumination.
Embodiments” include an image sensor consisting of a semiconductor substrate; multiple pixel regions each comprising an optically responsive layer over the substrate, the optically sensing layer positioned to receive light; and a pixel-circuit for each region. Each pixel circuit comprises a charge storage circuit and a read-out circuit. The charge store and the reader are in electrical communication with each pixel’s respective optically-sensitive layer. In this way, after illumination of at least one of the pixels, the dark signals it displayed before the higher-than-100-lux lighting, the dark signal it.
Embodiments” include an image sensor consisting of a semiconductor substrate; multiple pixel regions comprising an optically responsive layer over the substrate. Each pixel region is positioned to receive light. A first electrode is in electrical communication with both the semiconductor substrate as well as the optically-sensitive layer. The second electrode is in communication with both the semiconductor substrate. The first electrode forms a Schottky connection with the optically-sensitive layer. This Schottky contact allows the second electrode to communicate with the semiconductor substrate.
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