Image courtesy of Virginie Drujon-Kippelen
The first all-polymeric “plastic” organic solar cell on a flexible substrate uses an electron-collecting electrode that incorporates a high-conductivity polymer modified by an amine-containing polymer for improved performance.
Using an air-stable polymer, researchers discovered a way to significantly reduce the amount of energy needed to increase the power conversion efficiency for electrodes made from a wide range of conducting materials, including metals, oxides, polymers and graphene. Using this method enabled them to construct the first completely organic solar cell in which the substrate, active layer, and both electrodes are all made from “plastics”.
Through this “universal” approach, reactive metals can be replaced with less expensive, more stable electrodes, including conducting polymers, allowing the development of low-cost electronic devices manufactured under environmentally-friendly conditions.
Organic-based thin-film optoelectronics, such as solar cells, hold great potential as affordable consumer electronics. However, most printed optoelectronics require at least one electrode be a metal having a work function (the amount of energy needed to remove an electron) that is low enough to inject electrons into, or collect, electrons from an organic semiconductor. Unfortunately such metals are very reactive and easily oxidized, which reduces performance of the electrode. To avoid this problem, a controlled fabrication environment and protective barrier are needed to prevent water and/or oxygen exposure, increasing manufacturing complexity and cost. Researchers at Georgia Tech, part of the Center for Interface Science: Solar Electric Materials (CISSEM) EFRC, discovered a universal approach, i.e., applicable to many materials, for producing a low work function electrode that is stable in air. By “sticking” (through physisorption) an ultrathin layer (1 to 10 nanometers) of a commercially available, environmentally-friendly polymer with amine-containing aliphatic chains to a wide range of conductor surfaces, an air-stable, high performance electrode was created. To illustrate this approach’s promise, the researchers demonstrated, for the first time, a completely plastic organic solar cell on a flexible substrate, an approach that would lower manufacturing costs for solar cells and other electronics.
Georgia Institute of Technology
Neal R. Armstrong
Director of the Center for Interface Science: Solar Electric Materials EFRC
DOE Office of Science, Office of Basic Energy Sciences, Energy Frontier Research Centers (EFRC) Program (Y.Z., J.S., J.M., H.C., H.L., P.W., S.B., J.-L.B., S.R.M., and S.G.); NSF Science and Technology Centers Program (C.F.-H., J.K., E.N., and A.D.), Office of Naval Research (T.M.K. and B.K.); NSF grants (A.K., H.S.), DOE Office of Science, Office of Basic Energy Sciences, Materials Science and Engineering Division (W.H. and T.P.); Deutsche Forschungsgemeinschaft postdoctoral fellowship program (J.M.); National Defense Science and Engineering Graduate Fellowship program and NSF graduate research fellowship (A.J.G.).
Zhou, Yinhua; Fuentes-Hernandez, Canek; Shim, Jae Won; Meyer, Jens; Giordano, AnthonyJ.; Li, Hong; Winget, Paul; Papadopoulos, Theodoros; Cheun, Hyeunseok; Kim, Jungbae; Fenoll, Mathieu; Dindar, Amir; Haske, Wojciech; Najafabadi, Ehsan; Kahn, TalhaM.; Sojoudi, Hossein; Barlow, Stephen; Graham, Samuel; Brédas, Jean-Luc; Marder, SethR.; Kahn, Antoine; and Kippelen, Bernard “ A Universal Method to Produce Low–Work Function Electrodes for Organic Electronics” Science, 336(6079), 327-332 (2012). [DOI: 10.1126/science.1218829]
DOE Office of Science, Stories of Discovery & Innovation
Center for Interface Science: Solar Electric Materials EFRC
BES, MSE, EFRCs
Collaborations, Non-DOE Interagency Collaboration, International Collaboration