To improve characteristics, reliability, and the like of a solar cell element, the solar cell element includes: a semiconductor substrate which includes a first main surface and a second main surface that is positioned opposite to the first main surface, and in which a p-type semiconductor region and an n-type semiconductor region are stacked in such a manner that the p-type semiconductor region is positioned closest to the first main surface and the n-type semiconductor region is positioned closest to the second main surface; a first passivation layer which is disposed on the p-type semiconductor region that is positioned closest to the first main surface, and which includes aluminum oxide; and a first protective layer that is disposed on the first passivation layer. The first protective layer includes an oxide that contains at least one kind of zirconium and hafnium.

A nitride semiconductor light-emitting device with periodic gain active layers includes an n-type semiconductor layer, a p-type semiconductor layer and a resonator. The device further includes a plurality of active layers disposed between the n-type and p-type semiconductor layers so as to correspond to a peak intensity position of light existing in the resonator and at least one interlayer disposed between the active layers. The active layer disposed at the p-type semiconductor layer side has a larger light emission intensity than the active layer disposed at the n-type semiconductor layer side.

Provided are: a light-emitting layer for a perovskite light-emitting device; a method for manufacturing the same; and a perovskite light-emitting device using the same. The method of the present invention for manufacturing a light-emitting layer for an organic and inorganic hybrid perovskite light-emitting device comprises a step of forming a first nanoparticle thin film by coating, on a member for coating a light-emitting layer, a solution comprising organic and inorganic perovskite nanoparticles including an organic and inorganic perovskite nanocrystalline structure. Thereby, a nanoparticle light emitter has therein an organic and inorganic hybrid perovskite having a crystalline structure in which FCC and BCC are combined; forms a lamella structure in which an organic plane and an inorganic plane are alternatively stacked; and can show high color purity since excitons are confined to the inorganic plane. In addition, it is possible to improve the luminescence efficiency and luminance of a device by making perovskite as nanoparticles and then introducing the same into a light-emitting layer.

Disclosed herein is the formation of p-type transparent conducting oxides (TCO) having a structure of Mg.sub.xNi.sub.1-xO or Zn.sub.xNi.sub.1-xO. These structures disrupt the two-dimensional confinement of individual holes (the dominant charge carrier transport mechanism in pure NiO) creating three-dimensional hole transport by providing pathways for hole transfer in directions that are unfavorable in pure NiO. Forming these structures preserves NiO's transparency to visible light since the band gaps do not deviate significantly from that of pure NiO. Furthermore, forming Mg.sub.xNi.sub.1-xO or Zn.sub.xNi.sub.1-xO does not lead to hole trapping on O ions adjacent to Zn and Mg ions. The formation of these alloys will lead to creation of three-dimensional hole transport and improve NiO's conductivity for use as p-type TCO, without adversely affecting the favorable properties of pure NiO.

A photovoltaic device cell comprising a first light transmissive electrical contact, an active region, a second light transmissive electrical contact, and a layered structure enclosing the active region, the layered structure being formed of two parts, a first part underlying the first light transmissive electrical contact and a second part overlying the second electrical contact and wherein the constants of the layers in these layered structures are interdependent such that light is localized within the active region.

A flexible dye-sensitized solar cell includes: a fiber layer formed of nanofibers; a conductive electrode layer formed on one side of the fiber layer; a photoelectrode layer formed on the conductive electrode layer; a counter electrode layer formed on the other side of the fiber layer; a sealing member for enclosing the fiber layer, the conductive electrode layer, the counter electrode layer and the photoelectrode layer therein so as to seal said layers from the outside; and an electrolyte infiltrated into the fiber layer. A cell body in which an electrode and a photoelectrode are formed on one surface of the fiber that contains an electrolyte therein and a counter electrode is formed on the other side of the fiber is sealed with a polymer film, thus forming a flexible solar cell having an excellent sealing structure for preventing the electrolyte from leaking out of the cell even when pressure is externally applied.

An optical device includes an active layer that includes at least two outer barriers and at least one coupled quantum well that is inserted between the at least two outer barriers. Each coupled quantum well includes at least three quantum well layers and at least two coupling barriers that are respectively provided between the at least three quantum well layers. Thicknesses of two quantum well layers disposed at opposite end portions of the at least three quantum well layers are less than a thickness of the other quantum well layer disposed between the two quantum well layers disposed at the opposite end portions. A bandgap of the two quantum well layers disposed at the opposite end portions may be higher than a bandgap of the other quantum well layer disposed between the two quantum well layers.

An optical device includes an active layer that includes at least two outer barriers and at least one coupled quantum well that is inserted between the at least two outer barriers. Each coupled quantum well includes at least three quantum well layers and at least two coupling barriers that are respectively provided between the at least three quantum well layers. Thicknesses of two quantum well layers disposed at opposite end portions of the at least three quantum well layers are less than a thickness of the other quantum well layer disposed between the two quantum well layers disposed at the opposite end portions. A bandgap of the two quantum well layers disposed at the opposite end portions may be higher than a bandgap of the other quantum well layer disposed between the two quantum well layers.

An solar cell is provided comprising a photoelectric conversion layer formed on a substrate formed of a semiconductor material, and a first finger electrode formed of printed conductive paste to a main surface side of the photoelectric conversion layer, wherein an average of standard deviations of heights of uneveness on a surface of the first finger electrode is 5.0 μm or less. The first finger electrode may be formed on a back surface side of the solar cell opposite to a light-receiving surface side. The substrate may be a crystalline silicon substrate. The photoelectric conversion layer may comprise the crystalline silicon substrate, an amorphous silicon layer formed on the substrate, and a transparent conductive oxide film formed on the amorphous silicon layer. The first finger electrode may be provided on the transparent conductive oxide film.

A semiconductor device includes a semiconductor substrate, a photoelectric conversion element, a first isolation insulating film, and a current blocking region. The first isolation insulating film is formed around the photoelectric conversion element. The current blocking region is formed in a region between the photoelectric conversion element and the first isolation insulating film. The current blocking region includes an impurity diffusion layer, and a defect extension preventing layer disposed in contact with the impurity diffusion layer to form a twin with the impurity diffusion layer. The defect extension preventing layer has a different crystal structure from that of the impurity diffusion layer. At least a part of the current blocking region is disposed in contact with the first isolation insulating film.