Patent ID: 7834266

Claim:
A photovoltaic device, comprising: a first electrode; a second electrode arranged opposite to the first electrode; a photoactive layer arranged between the first electrode and the second electrode, the photoactive layer generating electrons and holes when absorbing light, the photoactive layer comprising an electron donor material and an electron acceptor material; a buffer layer arranged between the photoactive layer and the second electrode, the buffer layer comprising a compound including an aromatic organic cation and an anion, the compound being in a quantity ranging from about 30 wt % to 100 wt % with respect to the entire weight of the buffer layer; and wherein the aromatic cation is expressed as Chemical Formula 1: wherein X 1 and X 2 are NR c R d , where R c and R d are the same or independently selected from the group consisting of H and an alkyl group; R a is one selected from the group consisting of H, an alkyl group, a substituted aryl group, and an unsubstituted aryl group; and R b is one selected from the group consisting of H and an alkyl group.