A solar cell has a high ability to prevent recombination of electrons near the cell surface, wherein a surface of a p-type substrate at a surface is provided with an n-type region subjected to a treatment with a phosphorus containing acid and a silicon nitride layer is then directly formed on the n-type region. The solar cell can be prepared at a low temperature by a method comprising 1) a step of subjecting the n-type region to a phosphorus containing acid treatment at a low temperature and 2) a step of forming a silicon nitride by a vacuum and thermal CVD method.
The present invention provides a method for producing a solar cell comprising the step of immersing a silicon substrate in an etching solution which includes an aqueous sodium carbonate (Na.sub.2 CO.sub.3) solution, optionally an aqueous sodium hydroxide (NaOH) solution and/or an aqueous sodium bicarbonate (NaHCO.sub.3) solution to form minute concave and convex patterns on the surface of the silicon substrate. This method allows quite uniform textures to be formed on the crystal faces while avoiding the problem of disposal of isopropyl.
A solar battery cell having textures formed in a texture region on a light-receiving surface thereof, except for a site where a surface electrode is formed, wherein the textures formed in a peripheral portion of the texture region have a different size from the textures formed in an inside portion located inside of the peripheral portion.
A method for producing a thin film solar cell includes preparing a substrate of a low purity material and having opposed front and rear surfaces; forming an insulating film on the front surface of the substrate; forming a second conductivity type active layer of a high purity material on the insulating film with a front surface exposed; forming a second conductivity type semiconductor region within the active layer, reaching the front surface, to produce a p-n junction for light-to-electricity conversion; forming an anti-reflection film on the front surface of the active layer, the anti-reflection film reducing reflection of incident light; forming a surface electrode in contact with the front surface of the active layer; adhering the front surface side of the active layer to a supporting plate and selectively etching the low purity substrate from the rear surface to form a supporting substrate supporting the active layer; and forming a rear electrode on the rear surface of the supporting substrate contacting the active layer.
