title: Organic photovoltaic devices based on an acceptor of solution-processable functionalized graphene.
abstract: We prepared the exfoliation of graphite, which was necessary for the production of graphene sheets that are desirable for the fabrication of nano-composites. Then a Solution-Processable Functionalized Graphene (SPFGraphene) with functionalization groups doped with P3HT hybrid thin film-based organic photovoltaic cells (OPVCs) was systematically identified using a general device structure of, ITO/PEDOT:PSS/P3HT:SPFGraphene/LiF/Al. The effect of annealing on the photoelectric properties of the SPFGraphene was analyzed by Fourier transform infrared FT-IR spectroscopy and solar cell performance. After treatment at different annealing temperatures, with an increase in the SPFGraphene content, the short-circuit current density J(SC) and power conversion efficiency PCE of the hybrid devices increased first, reaching the peak efficiency for the 10 wt% SPFGraphene content, and then decreased. After annealing at 160 degrees C, the device containing 10 wt% SPFGraphene showed the open-circuit voltage V(OC) of 0.73 V, the J(SC) value of 3.98 mA cm(-2), fill factor (FF) value of 0.36, the PCE value of 1.046%. After thermal annealing at 210 degrees C, with the removal of the functional groups and recovery of the pi-conjugated areas, the conductivity of the graphene sheet and the charge carrier-transport mobility increased greatly, the J(SC) value of the 10 wt% SPFGraphene content device increased to 4.2 mA cm(-2), the V(OC) value decreased to 0.59 V, which may be attributed to the altered work-function value of the functionalized graphene and low quasi-Fermi levels for electrons and holes, the FF value was 0.27, and the PCE was 0.669%, which is lower than the former one. The results indicated that annealing at the appropriate temperature can improve the device performance greatly, and the functionalized graphene is expected to be a competitive candidate in organic photovoltaic applications because it is soluble, cheap, easily prepared, stable, and inert against the ambient conditions.
authors.affiliation: Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Optoelectronic Technology, Beijing Jiaotong University, Beijing 100044, P. R. China.
authors.forename: Jigang
authors.initials: J
authors.lastname: Wang
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Wang
authors.forename: Dawei
authors.initials: D
authors.lastname: He
authors.forename: Hongpeng
authors.initials: H
authors.lastname: Wu
authors.forename: Haiteng
authors.initials: H
authors.lastname: Wang
authors.forename: Pan
authors.initials: P
authors.lastname: Zhou
authors.forename: Ming
authors.initials: M
authors.lastname: Fu
authors.forename: Ke
authors.initials: K
authors.lastname: Jiang
authors.forename: Wei
authors.initials: W
authors.lastname: Chen