Hitachi, Ltd.

Tsuyoshi Uematsu

Yoshiaki Yazawa

Ken Tsutsui

Hiroyuki Ohtsuka

Yoshinori Miyamura

Tadashi Saitoh

Terunori Warabisako

Shin-ichi Muramatsu

Junko Minemura

Yasuhiro Kida

To form an impurity diffusion layer on only one side of a semiconductor substrate at least one semiconductor substrate and at least one diffusion protecting plate are put close to each other and a first impurity diffusion is perfomed on them, or at least one semiconductor substrate and at least one diffusion protecting plate are put close to each other and a first impurity diffusion is performed on them and then the semiconductor substrate and the diffusion protecting plate are arranged such that those sides on which the impurity diffusion has been performed face each other and a second impurity diffusion is performed. The diffusion protecting plate may be replaced by a semiconductor substrate. The first and second impurity diffusions may be performed using an impurity of the same conductivity type.

Photovoltaic device and making of the same

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

An opto-electric transducing element and a method for producing the same use a corrugated semiconductor substrate to produce an opto-electric transducing element. The element has a reduced effective thickness and an improved opto-electric conversion efficiency, while maintaining the mechanical strength.

Method for producing opto-electric transducing element

A photo-electric converting device has a plurality of emitters with a non-circular or non-dot shape in order to improve the photo-electric converting efficiency. The distance between the adjacent emitters has a predetermined relation to the average diffusion length of the minority carriers in a base layer in order to further improve the photo-electric conversion efficiency. The device is formed to have groove structures to restrain the photo-electric conversion loss due to reflected light.

Growing community of inventors

Kodaira, Japan

Tsuyoshi Uematsu