title: High-performance of PEDOT/PSS free organic solar cells on an air-plasma-treated ITO substrate.
abstract: In this work, we demonstrate the high-performance of a PEDOT:PSS free organic photovoltaic cell (OPVC) using an air-plasma modified ITO surface, followed by controlled solvent evaporation and annealing of the P3HT:PCBM photoactive layer. Ultraviolet photoelectron spectroscopy (UPS), X-ray photoelectron spectroscopy (XPS), and conductive atomic force microscopy (c-AFM) results show that the work function of ITO was increased to as high as that of PEDOT:PSS (5.2 eV) after air-plasma treatment, along with significantly enhanced electrical homogeneity. From the dynamic secondary ion mass spectroscopy (DSIMS) results, we confirm that the thermodynamic stability of the slow-dried active layer is attributed to the uniform vertical compositional distribution on the air plasma treated ITO surface, even after thermal annealing at 150 °C for 10 min. The resulting device has an open-circuit voltage of 0.65 V, a fill factor of 63%, and a power conversion efficiency of 3.38%, providing a high performance PEDOT:PSS free OPVC device.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology , 335 Gwahangno, Yuseong-gu, Daejeon 305-701, Korea.
authors.forename: Jong Kil
authors.initials: JK
authors.lastname: Choi
authors.forename: Ming Liang
authors.initials: ML
authors.lastname: Jin
authors.forename: Cheng Jin
authors.initials: CJ
authors.lastname: An
authors.forename: Dae Woo
authors.initials: DW
authors.lastname: Kim
authors.forename: Hee-Tae
authors.initials: HT
authors.lastname: Jung