Study Of Controlled Fabrication Of Dye-Sensitized Solar Cells By Layer-by-Layer Self-Assembled Method

As a third generation technology utilizing solar energy, dye-sensitized solar cells have achieved a number of breakthroughs after decades of development. It has the advantages of the low cost and the simple production process, but the lower photoelectric conversion efficiency restricted its development. Our target is to improve charge transmission capacity, and reduce the charge recombination. The structure of dye layers in dye-sensitized solar cells can be controlled through layer-by-layer self-assembly technology. Our works focused on the enhancement of organic opto-electronic and optical properties of thin films by changing the connection way of the inorganic-organic interfaces.Layers can be assembled through interactions between molecules to spontaneously form supramolecular structure with a particular function. First of all, we have synthesized the diazonium salt according to our group previous paper. We built bridges between inorganic materials and N719 dye through photodecomposition of diazonium group under UV irradiation. The optimized biPhN2+ upload time was 24 h determined by monitoring UV-vis spectra. Secondly, the optimized of N719 upload time was 12 h in the TiO2-biPhN2+-N719 system. Meanwhile, we proceeded with the XPS and IR characterization in order to test that relevant functional group and element have been successfully assembled in the films.In addition, the study on the fabrication of photo-anode in dye-sensitized solar cells was also carried out. The experimental results confirmed that 3-2 structure of anode, which consisted of the three layers of 20 nm Ti O2 and two scattering layers of 400 nm TiO2, had higher photovoltaic performances. We built TiO2-N719 and TiO2-biPhN2+-N719 two kinds of dye-sensitized solar cells, and test their I-V characteristics. The filling factor in TiO2-biPhN2+-N719 solar cell was 0.59, and photoelectric conversion efficiency was 7.06 %.