A photodetector designing method includes, according to various requirements required by an application equipped with a photodetector including a photoelectric conversion layer having a superlattice structure mostly composed of amorphous selenium, a step of determining a form of the photodetector; a step of determining a type of a substrate suitable for a wavelength to be detected by the photoelectric conversion layer among the requirements, a step of calculating a multiplication factor M representing an amplification gain generated in a process of tunneling in the superlattice structure, and a step of determining, as a layer thickness of the photoelectric conversion layer, a thickness obtained by multiplying a thickness per one layer of the superlattice structure by the number of layers N.sub.SL of the superlattice structure on the assumption that the multiplication factor M is approximate to the number of layers N.sub.SL.

A photodetector designing method includes, according to various requirements required by an application equipped with a photodetector including a photoelectric conversion layer having a superlattice structure mostly composed of amorphous selenium, a step of determining a form of the photodetector; a step of determining a type of a substrate suitable for a wavelength to be detected by the photoelectric conversion layer among the requirements, a step of calculating a multiplication factor M representing an amplification gain generated in a process of tunneling in the superlattice structure, and a step of determining, as a layer thickness of the photoelectric conversion layer, a thickness obtained by multiplying a thickness per one layer of the superlattice structure by the number of layers N.sub.SL of the superlattice structure on the assumption that the multiplication factor M is approximate to the number of layers N.sub.SL.

An imaging device that facilitates pooling processing. A pixel region includes a plurality of pooling modules and an output circuit, the pooling module includes a pooling circuit and a comparison module, the pooling circuit includes a plurality of pixels and an arithmetic circuit, and the comparison module includes a plurality of comparison circuits and a determination circuit. The pixel can obtain a first signal through photoelectric conversion, and can multiply the first signal by a given scaling factor to generate a second signal. The pooling circuit adds a plurality of second signals in the arithmetic circuit to generate a third signal, the comparison module compares a plurality of third signals and outputs the largest third signal to the determination circuit, and the determination circuit determines the largest third signal and binarizes it to generate a fourth signal. In the imaging device, the pooling module performs pooling processing in accordance with the number of pixels and outputs data obtained by the pooling processing.

A compound semiconductor which has an improved thermoelectric performance index together with excellent electrical conductivity, and thus may be utilized for various purposes such as a thermoelectric conversion material of thermoelectric conversion devices, solar cells, and the like, and to a method for preparing the same.

A photomultiplier containing a solid-state photoconductive film composed of amorphous selenium (a-Se) is provided. In the a-Se containing photomultiplier, a hole-blocking layer is provided that maximizes gain and maintains low dark conductivity. Also, the hole-blocking layer achieves reliable and repeatable impact ionization without irreversible breakdown. The hole-blocking layer is a non-insulating metal oxide having a dielectric constant (k) of greater than 10.

A photomultiplier containing a solid-state photoconductive film composed of amorphous selenium (a-Se) is provided. In the a-Se containing photomultiplier, a hole-blocking layer is provided that maximizes gain and maintains low dark conductivity. Also, the hole-blocking layer achieves reliable and repeatable impact ionization without irreversible breakdown. The hole-blocking layer is a non-insulating metal oxide having a dielectric constant (k) of greater than 10.

An imaging device capable of executing image processing is provided. A structure is employed in which a photoelectric conversion element, a first transistor, a second transistor, and an inverter circuit are included; one electrode of the photoelectric conversion element is electrically connected to one of a source and a drain of the first transistor; the other of the source and the drain of the first transistor is electrically connected to one of a source and a drain of the second transistor; the one of the source and the drain of the second transistor is electrically connected to an input terminal of the inverter circuit; and data obtained by photoelectric conversion is binarized and output.

Selenium-fullerene heterojunction solar cells and techniques for fabrication thereof are provided. In one aspect, a method of forming a solar cell includes: forming a front contact on a substrate; depositing an n-type semiconducting layer on the front contact, wherein the n-type semiconducting layer comprises a fullerene or fullerene derivative; forming a p-type chalcogen absorber layer on the n-type semiconducting layer; depositing a high workfunction material onto the p-type chalcogen absorber layer, wherein the high workfunction material has a workfunction of greater than about 5.2 electron volts; and forming a back contact on the high workfunction material. Solar cells and other methods for formation thereof are also provided.

Selenium-fullerene heterojunction solar cells and techniques for fabrication thereof are provided. In one aspect, a method of forming a solar cell includes: forming a front contact on a substrate; depositing an n-type semiconducting layer on the front contact, wherein the n-type semiconducting layer comprises a fullerene or fullerene derivative; forming a p-type chalcogen absorber layer on the n-type semiconducting layer; depositing a high workfunction material onto the p-type chalcogen absorber layer, wherein the high workfunction material has a workfunction of greater than about 5.2 electron volts; and forming a back contact on the high workfunction material. Solar cells and other methods for formation thereof are also provided.

An imaging device that facilitates pooling processing. A pixel region includes a plurality of pooling modules and an output circuit, the pooling module includes a pooling circuit and a comparison module, the pooling circuit includes a plurality of pixels and an arithmetic circuit, and the comparison module includes a plurality of comparison circuits and a determination circuit. The pixel can obtain a first signal through photoelectric conversion, and can multiply the first signal by a given scaling factor to generate a second signal. The pooling circuit adds a plurality of second signals in the arithmetic circuit to generate a third signal, the comparison module compares a plurality of third signals and outputs the largest third signal to the determination circuit, and the determination circuit determines the largest third signal and binarizes it to generate a fourth signal. In the imaging device, the pooling module performs pooling processing in accordance with the number of pixels and outputs data obtained by the pooling processing.