NOVELTY - The solar cell useful in a device, comprises a transparent substrate (110), a transparent tin-doped indium oxide anode (120) formed on the transparent substrate, a positive-type semiconductor layer (130) having a thickness of 5-80 nm formed on the anode, an active organic layer (140) formed on the semiconductor layer, a lithium fluoride layer (150) formed on the active organic layer, and an aluminum metallic cathode formed on the lithium fluoride layer. The semiconductor layer is transparent and adapted for blocking electrons leakage from the active organic layer to the anode.    USE - The solar cell is useful in a device (claimed).    ADVANTAGE - The solar cell has an effective electron-blocking layer by preventing current leakage and consequent counter-diode formation, high mechanical flexibility, and high power conversion efficiencies thus reducing the shortcoming of cells in the solar cell device, and can be easily and economically manufactured with light-weight and high throughput.    DETAILED DESCRIPTION - The solar cell useful in a device, comprises a transparent substrate (110), a transparent tin-doped indium oxide anode (120) formed on the transparent substrate, a positive-type semiconductor layer (130) having a thickness of 5-80 nm formed on the anode, an active organic layer (140) formed on the semiconductor layer, a lithium fluoride layer (150) formed on the active organic layer, and an aluminum metallic cathode formed on the lithium fluoride layer. The semiconductor layer is transparent and adapted for blocking electrons leakage from the active organic layer to the anode while transporting holes from the active organic layer to the anode. The active organic layer comprises an electron-donating organic material and an electron-accepting organic material, where the ratio of the organic materials in the active organic layer is 1:1 in weight. INDEPENDENT CLAIMS are included for:    (1) a method of fabricating a solar cell; and    (2) a method for forming a solar cell device with the solar cells in a stack.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of solar cell with an interfacial electron-blocking/hole-transporting layer.    Transparent substrate (110)    Anode (120)    Semiconductor layer (130)    Active organic layer (140)    Lithium fluoride layer. (150)