Patent ID: 7888593

Claim:
A solar cell, comprising: a. an anode; b. an active organic layer comprising an electron-donating organic material and an electron-accepting organic material; and c. an interfacial layer formed between the anode and active organic layer, wherein the interfacial layer comprises a hole-transporting polymer characterized with a hole-mobility higher than that of the electron-donating organic material in the active organic layer, and a small molecule characterized with a hole-mobility higher than that of the electron-donating organic material in the active organic layer and capable of crosslinking on contact with air, wherein the interfacial layer is adapted such that the highest occupied molecular orbital (HOMO) levels of the hole-transporting polymer and the small molecule are aligned with the HOMO level of the electron-donating organic material in the active organic layer so that holes generated in the active organic layer are able to travel through the interfacial layer to collection at the anode without an energetic barrier, wherein the hole-transporting polymer comprises poly(9,9-dioctylfluorene-co-N-(4-(3-methylpropyl))diphenylamine) (TFB), and wherein the small molecule comprises 4,4′-bis[(p-trichlorosilylpropylphenyl)phenylamino]biphenyl (TPDSi 2 ).