Fig. 1. Schematic illustration of graphene growth on glass substrate by vertical-glass model (The inset shows the vertical glass substrate set up).

Fig. 2. SEM image of graphene on a quartz glass with growth time of 25 min (a) and 35 min (b). The bright area corresponds to the bare substrate made by a scratch.

Fig. 3. High-magnification SEM images of graphene islands on glass surface with growth time of 15 min (a), 25 min (b), 35 min (c) and 45 min (d).

Fig. 4. Representative Raman spectra of directly-grown graphene on glasses with different growth time.

Fig. 5. AFM images of graphene grown on quartz glasses with growth time of 15 min (a), 25 min (b), 35 min (c) and 45 min (d) and corresponding line profiles.

Fig. 6. UV-vis spectra of graphene films grown on quartz glass with different growth time and corresponding sheet resistance.

Fig. 7. Raman spectra of directly-grown graphene on horizontal glass configuration with different growth times.

Fig. 8. Photographs of bare glass (left) and graphene glass (right, growth time of 35 min) with drops of water (a), contact angles of water droplets on pristine glass (b) and graphene glass with growth time of 15 min (c), 25 min (d), 35 min (e), 45 min (f).

Fig. 9. Photographs of assembled electrode device (a), lighted up blue LED indictor through transparent conductive glass (b) and water droplet (～5 μL) disappearing in about 5 min under 30 V input voltage (c).