Recent Progress of Graphene-Based Photoelectrode Materials for Dye-Sensitized Solar Cells

Figure 3

(a) Sheet resistance (solid curves with half error bars in the plus direction) and corresponding average conductivity (short dashed curves) of the transparent graphene films (TGFs) as a function of the film thickness, with the plot in the log-log scale. Black and blue curves denote the TGFs produced on quartz and SiO₂/Si, respectively. (b) Illustration of the mechanism of the intermolecular condensation of nanographene 1 into graphitic networks. (c) A representative HRTEM image of a TGF (scale bar: 5 nm). (d) and (e) AFM height images () of 4 and 30 nm thick TGF surfaces, respectively (color scale: black to bright yellow, 10 nm). Each image is accompanied with a cross-sectional plot which has the same vertical scale [68].

(a)

(b)

(c)

(d)

(e)