The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jan. 22, 2002
Filed:
Sep. 19, 1997
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In preparing a solar cell, minute projections and recesses are uniformly formed in a surface of a single crystal silicon substrate or a polycrystal silicon substrate by dipping the substrate in an etching liquid of a mixed acid including a hydrofluoride acid, a nitric acid and an adjusting agent containing at least a phosphoric acid or a water-soluble carboxylic acid having a higher molecular weight than acetic acid for adjusting the etching rate of the etching liquid. A solar cell having a substrate in which spherical projections and recesses are formed in a surface thereof to which light is incident; an apparatus for producing a solar cell, and a wet etching apparatus to maintain a constant concentration of a nitric acid, are provided.