Hitachi, Ltd.

Junko Minemura

Yoshiaki Yazawa

Terunori Warabisako

Yoshinori Miyamura

Ken Tsutsui

Shin-ichi Muramatsu

Tsuyoshi Uematsu

Hiroyuki Ohtsuka

Akira Sato

Takeshi Kitatani

A light concentrator photovoltaic module includes a medium having a light receiving plane, a plurality of photovoltaic elements arranged in a spaced relationship with the light receiving plane, and a light reflecting plane for conducting light incident upon the light receiving plane but is not directly received by the photovoltaic elements to the photovoltaic elements. The light reflecting plane has a structure as viewed on a cross section in a plane transverse to the module light receiving plane and traversing adjacent two photovoltaic elements and a light reflecting member therebetween such that the light reflecting plane includes, at least two first inclined planes and at least two second inclined planes, the first inclined planes being rightwardly ascending while the second inclined planes are leftwardly ascending, respectively, at least two first inclined planes being arranged on a right side of a middle point of a distance between the adjacent two photovoltaic elements while at least two second inclined planes being arranged on a left side of the middle point.

Light concentrator photovoltaic module method of manufacturing same and light concentrator photovoltaic system

Disclosed is a photovoltaic module including a plurality of concentrators each having a light-incident plane and a reflection plane, and photo detectors. Each photo detector is in contact with one of the concentrators. The module is capable of effectively trapping light and effectively generating power throughout the year even if the module is established such that sunlight at the equinoxes is made incident on the light-incident planes not in a perpendicular manner but instead obliquely, for example, in the case where the module is established in contact with a curved plane of a roof, or the like. In this module, each concentrator is formed into such a shape as to satisfy a relationship in which the light trapping efficiency of first incident light tilted rightwardly from the normal line of the light-incident plane in the cross-section including the light-incident plane, reflection plane and photo detector is larger than the light trapping efficiency of second incident light tilted leftwardly from the normal line in the above cross-section. Also, these concentrators are arranged in one direction.

Photovoltaic device, photovoltaic module and establishing method of photovoltaic system

A light receiving element having excellent characteristics, including high sensitivity and high response speed, can be achieved by a light element comprising unit structures each having two pn junction semiconductor layers, and a lightly doped semiconductor layer having low impurity density, lower than those of the p-type regions and the n-type regions of the two pn junction semiconductor layers, and which is sandwiched between the two pn junction semiconductor layers. The p-type regions of the pn junction semiconductor layers are disposed opposite to each other on opposite sides of the lightly doped semiconductor layer, respectively, and the n-type regions of the pn junction semiconductor layers are disposed opposite to each other on the opposite sides of the lightly doped semiconductor layer, respectively. In a method of fabricating such a light receiving element, using controlled shutters or an ion beam apparatus, the layers are formed of optimum semiconductors, in an optimum thickness and in optimum impurity densities. In this structure, photogenerated carriers move mainly through the lightly doped semiconductor layer. Therefore, the lifetime of the carriers is increased, and the drift mobility of the carriers is enhanced, so that the light receiving element is able to function with a high sensitivity at a high response speed.

Light receiving element and a method of fabricating the same

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Kokubunji, Japan

Junko Minemura