Low-Cost Fabrication of Organic Photovoltaics and Polymer LEDs - Low-cost Nanomaterials: Toward Greener and More Efficient Energy Applications - page 256

Fig. 32 a The fabricated transparent metal electrode on glass. b The optical microscope image
of the fabricated transparent silver electrode. The line width of silver is 5 lm and the distance
between lines is 150 lm
Fig. 33 UV-Vis
transmittance spectra of bare
glass, ITO glass, and the
transparent Ag, Al mesh
electrodes
technique and successfully fabricated inverted type OPVs with the TMEs using
aluminum and silver with 150 lm cell size and 5 lm line width (Fig. 32 ). The
thickness of the patterned TMEs for both metals was 50 nm. Figure 33 shows the
UV-vis transmittance spectra from 200 to 1100 nm wavelength range of the TME.
The transmittance of Ag TME substrate was 85 %, which is comparable to ITO
glass. The transmittance of Al TME was 80 %, which is slightly lower than ITO
glass and Ag TME substrate. Inverted solar cells were fabricated with structure
shown in Fig. 34 . On the TME substrates, PEDOT:PSS was spun-coated to
planarize the TME patterns. Polyethylenimine ethoxylated (PEIE) solution was
coated subsequently to reduce the work-function of the PEDOT:PSS for it to
function as a cathode for extracting electrons [ 27 ]. Both P3HT:PC 61 BM and a low
band gap polymer PIDT-phanQ:PC 71 BM [ 28 ] bulk heterojunction system were