Development of Blocking Layer Paste for Making Module By Screen Printing Procedure

Abstract

Dye Sensitized Solar Cells(DSSCs) is the next generation solar cell that has various advantages different from existing solar cells such as high transmittance, various colors, and High PCE in low light. Building Integrated Photovoltaic (BIPV) is getting a lot of attention by using DSSCs. The blocking layers in DSSCs improve the adhesion between the conductive substrate and the semiconductor electrode, and also reduce the recombination and back reaction by prevent the loss of electrons generated by light. In general blocking layer solution;TiCl4 dip coat, is used for making unit cells. However, in the large-area module manufacturing process, the solution process is not suitable. In addition, screen printing is applied by pasting the blocking layer material rather than the conventional solution process because selective coating is necessary for the part that does not need blocking layer such as Ag grid of Z-type module or Pt electrode part of W-type module. In this study, we developed the blocking layer paste, which enables a large-area screen printing process with a higher transparent(77.6%) than the TiCl4 dip coating(71.1%) / spin coating method(74.8%) by controlling Ti precursor/vehicle. Through these studies, it can be used not only the application of large area modules but also replacing exist unit cell solution processes (TiCl4 dip coat, etc.).