Back-contact perovskite solar cells

Organic-inorganic hybrid perovskites have emerged as a promising light absorber for solar cells due to their remarkable optoelectronic properties. High-efficiency perovskite solar cells mainly employ a sandwich architecture in which the perovskite active layer is sandwiched between two selective contact layers. However, there is an inevitable optical loss in the sandwiched structure when the light propagates through the transparent conductive substrate and selective contact layer. In order to prevent the transmission loss, novel designs of back-contact structures are demonstrated for light illumination upon the perovskite. To achieve the back-contact structure, the selective contact layers and electrode are deposited and patterned on the substrate. The perovskite light absorber is finally deposited on top of the patterned electrode to complete the back-contact device. The photogenerated carriers (holes and electrons) are transported in the same direction and extracted by the selective contact layers. In this paper, we summarize recent advances in back-contact perovskite solar cells.