Hitachi, Ltd.

Yasuhiro Kida

Tadashi Saitoh

Koichi Suda

Keiichi Morita

Tsuyoshi Uematsu

Kunihiro Matsukuma

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.

Photo-electric converting device

In a method of manufacturing a solar cell including a p-n junction formed in a semiconductor substrate, impurity ions are implanted through a mask in the form of an oxide film covering a light receiving surface of the semiconductor substrate except an electrode forming part, thereby forming a p-n junction which is deep in an area beneath the electrode forming part but shallow in the remaining area. Formation of the shallow p-n junction improves the spectral sensitivity in a short wavelength range. Further, utilization of the oxide film as a passivation film can prevent shortening of the life time of minority carriers in the substrate due to heat treatment, thereby retarding the electron-hole recombination rate at the light receiving surface of the substrate.

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Hitachi, Japan

Yasuhiro Kida