Provided are a material that achieves higher sensitivity and higher resolution of a photoelectric conversion element for imaging, and a photoelectric conversion element using the above material. A material for a photoelectric conversion element for imaging including a carbazole compound represented by (Cz)-L.sup.1-(Cz) and having a structure in which two carbazole rings (Cz) are bonded with L.sup.1, wherein at least one of L.sup.1 and a substituent Ar substituted on the carbazole rings is a group having an aromatic ring structure selected from the following formula (4) or (5). (Here, a ring A is represented by formula (5A); X.sup.1 represents O, S, Se, NR, or N; and X.sup.2 represents O, S, or Se.)

Provided are a material that achieves higher sensitivity and higher resolution of a photoelectric conversion element for imaging, and a photoelectric conversion element using the above material. A material for a photoelectric conversion element for imaging including a carbazole compound represented by (Cz)-L.sup.1-(Cz) and having a structure in which two carbazole rings (Cz) are bonded with L.sup.1, wherein at least one of L.sup.1 and a substituent Ar substituted on the carbazole rings is a group having an aromatic ring structure selected from the following formula (4) or (5). (Here, a ring A is represented by formula (5A); X.sup.1 represents O, S, Se, NR, or N; and X.sup.2 represents O, S, or Se.)

A photo-capacitance sensor includes an input surface and one or more light sources arranged to illuminate a portion of the input surface. The photo-capacitance sensor also includes an array of photo-capacitors arranged to receive light from the one or more light sources which is reflected from an object in contact with, or proximate to, the illuminated portion of the input surface. The array of photo-capacitors is configured for detecting a reflective pattern of the object.

An imaging apparatus includes a first electrode, a second electrode, a photoelectric conversion layer, a charge injection layer, and a charge accumulation region. The second electrode opposes the first electrode. The photoelectric conversion layer is located between the first electrode and the second electrode, contains a donor semiconductor material and an acceptor semiconductor material, and generates a pair of an electron and a hole. The charge injection layer is located between the first electrode and the photoelectric conversion layer. The charge accumulation region is electrically coupled to the second electrode and accumulates the hole. An ionization potential of the charge injection layer is less than or equal to an ionization potential of the acceptor semiconductor material. Electron affinity of the charge injection layer is less than or equal to electron affinity of the acceptor semiconductor material. Light transmittance of the charge injection layer is greater than or equal to 70%.

A photoelectric conversion element includes (a-1) a first electrode 21 and a second electrode 22 disposed apart from each other, and (a-2) a photoelectric conversion material layer 30 disposed between the first electrode 21 and the second electrode 22. The photoelectric conversion material layer 30 is formed of the following structural formula (1). ##STR00001##

A particle sensing device is provided. The particle sensing device may include a light emitter configured to emit and output light into a light scattering space, and a light receiver provided in a maximum light scattering angle region. A maximum intensity of scattered light formed when the light emitted from the light emitter is scattered by a particle in the light scattering space may be obtained in the maximum light scattering angle region, and the light receiver may be configured to receive the scattered light incident thereon and generate a photocurrent signal.

A novel photoelectric conversion device that is highly convenient, useful, or reliable is provided. A photoelectric conversion device (550S) includes a first electrode (551S), a second electrode (552S), and a unit (103S); the unit (103S) is interposed between the first electrode (551S) and the second electrode (552S); the unit (103S) includes a first layer (113) and a second layer (114S); and the first layer (113) is interposed between the second electrode (552S) and the second layer (114S). The first layer (113) contains a first organic compound ETM, the first organic compound ETM has an electron-transport property, and the first organic compound ETM has a LUMO level in a first level LUMO1. The second layer (114S) contains a second organic compound CTM, the second organic compound CTM emits delayed fluorescent light at room temperature, and the second organic compound CTM has a LUMO level in a second level LUMO2. A difference between the second level LUMO2 and the first level LUMO1 is less than or equal to 1.0 eV.

An optical sensor includes a plurality of lower electrodes adjacent to one another, an organic material layer that includes a lower carrier transport layer including a plurality of first electrode covering parts each covering at least an upper surface of corresponding one of the plurality of lower electrodes, and a carrier mobility reducing part that is provided in at least a part of an area between the adjacent first electrode covering parts so as to reduce carrier mobility of the adjacent first electrode covering parts.

A photoactive device, comprising a first layer comprising a polymer of formula (1) or a salt thereof, a method comprising illuminating the photoactive device, a method of making the photoactive device, and a composition comprising the polymer of formula (1) and a dye. The photoactive device operates as an inverse phototransistor in which the current is higher in the absence of illumination and lower in the presence of illumination.

A novel and highly convenient, useful, or reliable material for a photoelectric conversion device is provided. The photoelectric conversion device includes a first electrode, a second electrode, a first layer, a second layer, and a third layer. The first layer is held between the first electrode and the second electrode; the second layer is held between the second electrode and the first layer; the third layer is held between the second electrode and the second layer; and the third layer has higher electron mobility than the first layer. The material is used in the second layer, the material contains an anthracene skeleton, and the anthracene skeleton is bonded to a diarylamino group, a diheteroarylamino group, or an arylheteroarylamino group.