Abstract: An organic solar cell includes a substrate; a first electrode; a second electrode disposed opposite the first electrode; a photoactive layer that is disposed between the first electrode and the second electrode, and that comprises n-type organic semiconductor material and p-type organic semiconductor material; and an intermediate layer that is disposed on at least one surface of the photoactive layer and that contains a compound represented by Formula 1 below: where R1, R2, R3, R4, R5, and R6 are each independently selected from the group consisting of hydrogen atoms, a carbonyl group, a hydroxyl group, a nitro group, an amino group, a sulfonyl group, a phosphoryl group, straight-chain or branched C1-C7 alkyl groups, and straight-chain or branched C8-C20 alkyl groups, wherein R1, R2, R3, R4, R5, and R6 are not all the same. The organic solar cells have enhanced photostability due to introduction of the intermediate layer.

Abstract: Disclosed is a conjugated polymer for an organic solar cell. The proportion of units containing no alkyl thiophene moieties in the conjugated polymer can vary to make the conjugated polymer suitable for use as an electron-donating organic semiconductor material in a small-area or large-area organic solar cell. Therefore, the use of the conjugated polymer ensures high energy conversion efficiency of the organic solar cell.

Abstract: Disclosed is a conjugated polymer for an organic solar cell. The proportion of units containing no alkyl thiophene moieties in the conjugated polymer can vary to make the conjugated polymer suitable for use as an electron-donating organic semiconductor material in a small-area or large-area organic solar cell. Therefore, the use of the conjugated polymer ensures high energy conversion efficiency of the organic solar cell.

Abstract: Disclosed are organic solar cells whose photostability is enhanced by the introduction of an intermediate layer. The organic solar cells are free from problems associated with poor photostability of conventional organic solar cells. Therefore, the organic solar cells can maintain their initial efficiency for a long time, achieving markedly improved life characteristics. In addition, the organic solar cells can be fabricated on a large scale.