Techniques for electrodepositing selenium (Se)-containing films are provided. In one aspect, a method of preparing a Se electroplating solution is provided. The method includes the following steps. The solution is formed from a mixture of selenium oxide; an acid selected from the group consisting of alkane sulfonic acid, alkene sulfonic acid, aryl sulfonic acid, heterocyclic sulfonic acid, aromatic sulfonic acid and perchloric acid; and a solvent. A pH of the solution is then adjusted to from about 2.0 to about 3.0. The pH of the solution can be adjusted to from about 2.0 to about 3.0 by adding a base (e.g., sodium hydroxide) to the solution. A Se electroplating solution, an electroplating method and a method for fabricating a photovoltaic device are also provided.

An imaging device which offers an image with high quality and is suitable for high-speed operation is provided. The imaging device includes a first region to an n-th region (n is a natural number of 2 or more and 16 or less) each including a first circuit, a second circuit, a third circuit, and a fourth circuit. The first to third circuits each include a transistor in which silicon is used in an active layer or an active region. The fourth circuit includes a photoelectric conversion element and a transistor in which an oxide semiconductor is used in an active layer. The first circuit includes a region overlapping with the fourth circuit. The third circuit includes a region overlapping with the fourth circuit.

An imaging device which offers an image with high quality and is suitable for high-speed operation is provided. The imaging device includes a first region to an n-th region (n is a natural number of 2 or more and 16 or less) each including a first circuit, a second circuit, a third circuit, and a fourth circuit. The first to third circuits each include a transistor in which silicon is used in an active layer or an active region. The fourth circuit includes a photoelectric conversion element and a transistor in which an oxide semiconductor is used in an active layer. The first circuit includes a region overlapping with the fourth circuit. The third circuit includes a region overlapping with the fourth circuit.

Disclosed are a solar cell and a method for manufacturing the same. The solar cell includes a substrate, a back electrode layer on the substrate, a light absorbing layer on the back electrode layer, a buffer layer on the light absorbing layer, and a window layer on the buffer layer. The buffer layer is formed through a chemical equation of (A.sub.xZn.sub.1-x)O(0≤x≤1), in which the A represents a metallic element.

A semiconductor device including pixels arranged in a matrix of n rows and m columns, in which the pixels in the m-th column are shielded from light, is provided.

A semiconductor device including pixels arranged in a matrix of n rows and m columns, in which the pixels in the m-th column are shielded from light, is provided.

Methods and devices that use alkali metal chalcohalides having the chemical formula A.sub.2TeX.sub.6, wherein A is Cs or Rb and X is I or Br, to convert hard radiation, such as X-rays, gamma-rays, and/or alpha-particles, into an electric signal are provided. The devices include optoelectronic and photonic devices, such as photodetectors and photodiodes. The method includes exposing the alkali metal chalcohalide material to incident radiation, wherein the material absorbs the incident radiation and electron-hole pairs are generated in the material. A detector is configured to measure a signal generated by the electron-hole pairs that are formed when the material is exposed to incident radiation.

Methods and devices that use alkali metal chalcohalides having the chemical formula A.sub.2TeX.sub.6, wherein A is Cs or Rb and X is I or Br, to convert hard radiation, such as X-rays, gamma-rays, and/or alpha-particles, into an electric signal are provided. The devices include optoelectronic and photonic devices, such as photodetectors and photodiodes. The method includes exposing the alkali metal chalcohalide material to incident radiation, wherein the material absorbs the incident radiation and electron-hole pairs are generated in the material. A detector is configured to measure a signal generated by the electron-hole pairs that are formed when the material is exposed to incident radiation.

A photoelectric conversion element includes a first electrode, a second electrode, a first layer, and a second layer. The first layer is provided between the first electrode and the second electrode. The second layer is provided between the first layer and the second electrode. The first layer contains selenium. The second layer contains In, Ga, Zn, and O. The second layer may contain an In—Ga—Zn oxide. The selenium may be crystalline selenium. The first layer functions as a photoelectric conversion layer. The second layer functions as a hole injection blocking layer. The In—Ga—Zn oxide may have a c-axis aligned crystal.

A photoelectric conversion element includes a first electrode, a second electrode, a first layer, and a second layer. The first layer is provided between the first electrode and the second electrode. The second layer is provided between the first layer and the second electrode. The first layer contains selenium. The second layer contains In, Ga, Zn, and O. The second layer may contain an In—Ga—Zn oxide. The selenium may be crystalline selenium. The first layer functions as a photoelectric conversion layer. The second layer functions as a hole injection blocking layer. The In—Ga—Zn oxide may have a c-axis aligned crystal.