Solar cell

A solar cell comprising a first cell and a second cell,

• the first cell comprising:
• a first substrate,
• a first electrode layer,
• a first electron transport layer,
• a first photoelectric conversion layer,
• a first hole transport layer, and
• a second electrode layer, disposed in the order stated, and
• the second cell comprising:
• a second substrate,
• a fourth electrode layer,
• a second hole transport layer,
• second photoelectric conversion layer,
• a second electron transport layer, and
• a third electrode layer, disposed in the order stated;
• wherein
• the first cell and the second cell are arranged such that there is a space between the second electrode layer and the third electrode layer, the space being filled with air or a filler,
• the first photoelectric conversion layer includes a first perovskite compound,
• the second photoelectric conversion layer includes a second perovskite compound,
• the first perovskite compound has a bandgap greater than a bandgap of the second perovskite compound, and
• the solar cell has one of the following configurations, (i), (ii), or (iii):
• (i) the first electrode layer and the fourth electrode layer are electrically connected to each other,
• (ii) the second electrode layer and the third electrode layer are electrically connected to each other, or
• (iii) the first electrode layer and the third electrode layer are electrically connected to each other, and the second electrode layer and the fourth electrode layer are electrically connected to each other.