Stacked solar cell

A stacked solar cell, comprising:

• a light absorption layer group comprising an excitation layer, a first electron transport layer group provided on a first side surface of the excitation layer, and a first hole transport layer group provided on a second side surface of the excitation layer;
• and
• a heterojunction layer group, wherein a second electron transport layer is provided as a first side surface of the heterojunction layer group and is in contact with the first hole transport layer group, and a second hole transport layer is provided as a second side surface of the heterojunction layer group;
• wherein the first hole transport layer group comprises a hole transport layer in contact with the excitation layer, a PN junction in contact with the hole transport layer, and a first light transport layer in contact with the PN junction, the first light transport layer is in contact with the second electron transport layer, and a refractive index of the first light transport layer is smaller than a refractive index of the second electron transport layer;
• wherein under the irradiation of sunlight, both the excitation layer and the heterojunction layer group are excited, and an electron generated by the excitation layer is transported out of the stacked solar cell through the first electron transport layer;
• a hole generated by the excitation layer flows to the heterojunction layer group through the first hole transport layer group and recombines with an electron generated by the heterojunction layer group, and a hole generated by the heterojunction layer group is transported out of the stacked solar cell from the second hole transport layer.