Efficient dye-sensitized solar cell sub-modules

Two topics with dye-sensitized solar cell (DSC) development were introduced. The one was development of an efficient glass–substrate 10 cm-by-10 cm DSC sub-modules with current-collecting Ag grids using N719 dye (ηac = 8.0%, Jsc = 16.8 mA/cm2, Voc = 0.71 V, ff = 0.67). Accelerated long-term stability tests were conducted using JIS C-8938 environmental and endurance test methods for amorphous-Si solar cell modules, which included a dry heat cycle test (−40 °C to 90 °C, 200 cycles), a heat–humidity test (−40 °C to 90 °C with 85% humidity, 10 cycles) and a light-soaking test (255 W/m2 (300–700 nm), 500 h). The results suggested DSC using methoxypropionitrile (MPN) electrolyte solvent has a promising future to commercialization of DSC. The other was development of a new preparation method for highly efficient plastic–substrate DSC. This method consisted of important basic technologies such as press without heat treatment, light-confining effect by light scattering TiO2 large particles, binder-free water paste of TiO2 and UV–O3 treatment of TiO2 photoelectrode. The plastic–substrate DSC prepared by this new method showed a very high efficiency, 8.1% (0.29 cm2) under simulated solar light (100 mW/cm2, AM1.5). Further, an efficient plastic–substrate 10 cm-by-10 cm DSC sub-module with current-collecting Ti grids using N719 dye (ηac = 4.5%, Jsc = 10.9 mA/cm2, Voc = 0.72 V, ff = 0.57) was successfully prepared.