Low-temperature fabrication of TiO(2) electrodes for flexible dye-sensitized solar cells using an electrospray process.
Hierarchically structured TiO2 (HS-TiO2) was prepared on a flexible ITO-PEN (polyethylene naphthalate) substrate via electrospray deposition using a commercially available TiO2 nanocrystalline powder in order to fabricate flexible DSSCs under low-temperature (<150 °C) conditions. The cell efficiency increased when using flexible ITO-PEN substrates post-treated by either a mechanical compression treatment or a chemical sintering treatment using titanium n-tetrabutoxide (TTB). The mechanical compression treatment reduced the surface area and porosity of the HS-TiO2; however, this treatment improved the interparticle connectivity and physical adhesion between the HS-TiO2 and ITO-PEN substrate, which increased the photocurrent density of the as-pressed HS-TiO2 cells. The electron diffusion coefficients of the as-pressed HS-TiO2 improved upon compression treatment, whereas the recombination lifetimes remained unchanged. An additional chemical sintering post-treatment involving TTB was tested for its effects on DSSC efficiency. The freshly coated TiO2 submitted to TTB hydrolysis in water at 100 °C yielded an anatase phase. TTB treatment of the HS-TiO2 cell after compression treatment yielded faster electron diffusion, providing an efficiency of 5.57% under 100 mW cm(-2), AM 1.5 global illumination.
Optoelectronic Materials Lab, Korea Institute of Science and Technology , Seoul 136-791, Korea.
Horim
H
Lee
Daesub
D
Hwang
Seong Mu
SM
Jo
Dongho
D
Kim
Yongsok
Y
Seo
Dong Young
DY
Kim
D003080:Cold Temperature; D004396:Coloring Agents / Q000737:chemistry; D004566:Electrodes; D011095:Polyethylenes / Q000737:chemistry; D012993:Solar Energy; D017971:Tin Compounds / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*
D004396:Coloring Agents; D011095:Polyethylenes; D017971:Tin Compounds; C009495:titanium dioxide; C109984:indium tin oxide; D014025:Titanium