Graphene for Transparent Electrodes and Organic Electronic Devices - Organic Solar Cells: Materials and Device Physics - page 82

Fig. 4.1 (a) Photograph of an unreduced (left most) and a series of high-temperature reduced GO
films of increasing thickness. Black scale bar is 1 cm. (b) Device structure and energy diagram of
the fabricated device with structure quartz/graphene/PEDOT:PSS/P3HT:PCBM/LiF/Al. (c) Opti-
cal transmittance spectra of graphene oxide film (*40 nm) and graphene films (*25 nm) with
different reduced methods. (d) Current density (filled symbols) and luminance (open symbols)
versus applied forward bias for an OLED on graphene (squares) and ITO (circles), with OLED
device structure anode/PEDOT:PSS/NPD(50 nm)/Alq 3 (50 nm)/LiF/Al as shown in the inset.
(e) External quantum efficiency (EQE) (filled symbols) and luminous power efficiency (LPE)
(open symbols) for an OLED on graphene film (squares) and ITO glass (circles). (a) Reproduced
with permission [ 24 ]. Copyright 2008, ACS. (b-c) Reproduced with permission [ 25 ]. Copyright
2010, Elsevier. (d-e) Reproduced with permission [ 6 ]. Copyright 2010, ACS
deposition, the insulating graphene oxide films were reduced through exposure to
hydrazine vapor and then annealed under inert conditions to render the material
electrically conductive. The electrical conductivity of the as-prepared graphene
film is closely related to the annealing temperature. At a given film thickness of
*25 nm, graphene film conductivity increased with the increase of the annealing