Solar cell substrate, thin-film solar cell, and multi-junction thin-film solar cell

A thin-film solar cell, comprising:

• a solar cell substrate having irregularities on a surface being in contact with a photo-electric conversion layer, light being incident on the solar cell substrate on the side of the irregularities,
• a height of the irregularities being set so that a root mean square height is in a range of 15 nm to 600 nm, and tan θ in a range of 0.10 to 0.20, where θ is an angle of incline of a surface of the irregularities with respect to an average line of the irregularities,
• said solar cell substrate having the photo-electric conversion layer being made up of at least one photo-electric conversion element.

A solar cell substrate having irregularities on a surface which is in contact with a photo-electric conversion layer, light being incident on the solar cell substrate on the other side of the irregularities,

• wherein:
• a height of the irregularities is set so that a root mean square height is in a range of 25 nm to 600 nm, and tan θ is in a range of 0.07 to 0.20, where θ is an angle of incline of a surface of the irregularities with respect to an average line of the irregularities.

A thin-film solar cell, comprising:

• a solar cell substrate having irregularities on a surface being in contact with a photo-electric conversion layer, light being incident on the solar cell substrate on the side of a surface opposite the surface with the irregularities,
• a height of the irregularities being set so that a root mean square height is in a range of 25 nm to 600 nm, and tan θ in a range of 0.07 to 0.20, where θ is an angle of incline of a surface of the irregularities with respect to an average line of the irregularities,
• said solar cell substrate having the photo-electric conversion layer being made up of at least one photo-electric conversion element.

A multi-junction thin-film solar cell, comprising:

• a plurality of photo-electric conversion elements on the opposite side of a side of a substrate on which light is incident;
• and
• an intermediate layer, having irregular surfaces, provided between at least one of any adjacent pairs of the photo-electric conversion elements, the irregularities of the intermediate layer partially having indentations in the form of a hemisphere or circular cone with a diameter in a range of 200 nm to 2000 nm.

A solar cell substrate having irregularities on a surface which is in contact with a photo-electric conversion layer, light being incident on the solar cell substrate on the side of the irregularities,

• wherein:
• a height of the irregularities is set so that a root mean square height is in a range of 20 nm to 400 nm, and tan θ is in a range of 0.15 to 0.25, where θ is an angle of incline of a surface of the irregularities with respect to an average line of the irregularities.

A solar cell substrate having irregularities on a surface which is in contact with a photo-electric conversion layer, light being incident on the solar cell substrate on the other side of the irregularities,

• wherein:
• a height of the irregularities is set so that a root mean square height is in a range of 25 nm to 400 nm, and tan θ is in a range of 0.07 to 0.15, where θ is an angle of incline of a surface of the irregularities with respect to an average line of the irregularities.