A tandem photovoltaic device includes a perovskite absorbing layer, a crystalline silicon absorbing layer and a single-layer electrical function layer connected in series to the two absorbing layers; a contact interface between the perovskite absorbing layer and the single-layer electrical function layer is a first series interface; and a contact interface between the crystalline silicon absorbing layer and the single-layer electrical function layer is a second series interface; wherein a conducting type at the second series interface is different from a conducting type at the first series interface, and the difference between the work functions is 0.3 eV and 0.3 eV.

An imaging device is provided. The imaging device may include a substrate having a first photoelectric conversion unit and a second photoelectric conversion unit at a light-incident side of the substrate. The second photoelectric conversion unit may include a photoelectric conversion layer, a first electrode, a second electrode above the photoelectric conversion layer, a third electrode, and an insulating material between the third electrode and the photoelectric conversion layer, wherein a portion of the insulating material is between the first electrode and the third electrode.

A photoelectric conversion element (10) according to an embodiment of the present disclosure includes: a first electrode (11); a second electrode (16) disposed to be opposed to the first electrode (11); a photoelectric conversion layer (13) provided between the first electrode (11) and the second electrode (16); and a buffer layer (14) provided between the second electrode (16) and the photoelectric conversion layer (13) and having both hole transportability and electron transportability.

A photoelectric conversion element (10) according to an embodiment of the present disclosure includes: a first electrode (11); a second electrode (16) disposed to be opposed to the first electrode (11); a photoelectric conversion layer (13) provided between the first electrode (11) and the second electrode (16); and a buffer layer (14) provided between the second electrode (16) and the photoelectric conversion layer (13) and having both hole transportability and electron transportability.

Photovoltaic devices with type II-VI semiconductor absorber materials having improved carrier extraction layers are described herein. Methods of treating semiconductor absorber layers and forming improved carrier extraction layers and p-type contact layers are described.

Photovoltaic devices with type II-VI semiconductor absorber materials having improved carrier extraction layers are described herein. Methods of treating semiconductor absorber layers and forming improved carrier extraction layers and p-type contact layers are described.

An oxamide ultraviolet absorber-doped perovskite active layer, including a perovskite film and an oxamide ultraviolet absorber doped therein, where the oxamide ultraviolet absorber is N-(2-ethoxyphenyl)-N-(2-ethylphenyl) oxamide, and a perovskite structure is represented by ABX.sub.3. A perovskite solar cell, including a conductive substrate layer, a lower interfacial transport layer, the perovskite active layer, an upper interfacial transport layer and a metal electrode arranged sequentially from bottom to top. Methods for preparing the perovskite active layer and the perovskite solar cell are also provided.

An oxamide ultraviolet absorber-doped perovskite active layer, including a perovskite film and an oxamide ultraviolet absorber doped therein, where the oxamide ultraviolet absorber is N-(2-ethoxyphenyl)-N-(2-ethylphenyl) oxamide, and a perovskite structure is represented by ABX.sub.3. A perovskite solar cell, including a conductive substrate layer, a lower interfacial transport layer, the perovskite active layer, an upper interfacial transport layer and a metal electrode arranged sequentially from bottom to top. Methods for preparing the perovskite active layer and the perovskite solar cell are also provided.

A tandem photovoltaic device includes a perovskite absorbing layer, a crystalline silicon absorbing layer and a single-layer electrical function layer connected in series to the two absorbing layers; a contact interface between the perovskite absorbing layer and the single-layer electrical function layer is a first series interface; and a contact interface between the crystalline silicon absorbing layer and the single-layer electrical function layer is a second series interface; wherein a conducting type at the second series interface is different from a conducting type at the first series interface, and the difference between the work functions is 0.3 eV and 0.3 eV.

A tandem photovoltaic device includes a perovskite absorbing layer, a crystalline silicon absorbing layer and a single-layer electrical function layer connected in series to the two absorbing layers; a contact interface between the perovskite absorbing layer and the single-layer electrical function layer is a first series interface; and a contact interface between the crystalline silicon absorbing layer and the single-layer electrical function layer is a second series interface; wherein a conducting type at the second series interface is different from a conducting type at the first series interface, and the difference between the work functions is 0.3 eV and 0.3 eV.