NOVELTY - The tandem solar cell comprises a top inverted solar cell (200) having inverted solar sub-cells (203), an interlayer (400) having conductive dots, and a bottom normal solar cell having normal solar sub-cells (303). The interlayer is connected to the top inverted solar cell. The bottom normal solar cell is connected to the interlayer. A solar sub-cell is constructed by the inverted solar sub-cell and normal solar sub-cell. The conductive dot connects the inverted solar sub-cell and adjacent normal solar sub-cell to construct a series/parallel connection of solar sub-cells structure.    USE - The organic tandem solar cell is useful as energy generators in satellite, space technology and mobile communication.    ADVANTAGE - The organic tandem solar cell can be economically, effectively and easily manufactured with light weight, good flexibility and electric conductivity, ruggedness, impact resistance, excellent energy conversion efficiency and improved quality.    DETAILED DESCRIPTION - The tandem solar cell comprises a top inverted solar cell (200) having inverted solar sub-cells (203), an interlayer (400) having conductive dots, and a bottom normal solar cell having normal solar sub-cells (303). The interlayer is connected to the top inverted solar cell. The bottom normal solar cell is connected to the interlayer. A solar sub-cell is constructed by the inverted solar sub-cell and normal solar sub-cell. The conductive dot connects the inverted solar sub-cell and adjacent normal solar sub-cell to construct a series/parallel connection of solar sub-cells structure. The top inverted solar cell further comprises a first substrate for forming the inverted solar sub-cells, and the bottom solar cell further comprises a second substrate for forming the normal solar sub-cells. The first and second substrates comprise a glass substrate or a flexible substrate having a transparent conductive oxide film. The inverted solar sub-cell comprises a hole blocking layer, a first active layer connected to the hole blocking layer, an electron blocking layer connected to the first active layer, and a first top electrode connected to the electron blocking layer. The materials of the hole blocking layer are oxidizing materials. The materials of the first and second top electrode comprise metal materials with high work function or other transparent conductive oxide. The bottom solar sub-cell comprises a hole transport layer, a second active layer connected to the hole transport layer, and a second top electrode connected to the second active layer. The first and second active layers comprise an interface of donor/acceptor. The materials of the interlayer comprise metal or semiconductor materials with bipolar transport property. An INDEPENDENT CLAIM is included for a fabricating method of a tandem solar cell.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a tandem solar cell.    Top inverted solar cell (200)    Substrate (201, 301)    Inverted solar sub-cells (203)    Normal solar sub-cells (303)    Interlayer. (400)