Material development for dye solar modules: results from an integrated approach

Abstract

In this paper, we report on the outcome of a German network project conducted with 12 partners from universities and research institutes on the material development of dye solar cells (DSC). We give an overview in the field and evaluate the concept of monolithic DSC further with respect to upscaling and producibility on glass substrates. We have developed a manufacturing process for monolithic DSC modules which is entirely based on screen printing. Similar to our previous experience gained in the sealing of standard DSC, the encapsulation of the modules is achieved in a fusing step by soldering of glass frit layers. For use in monolithic DSC, a platinum free, conductive counter electrode layer, showing a charge transfer resistance of R CT < 1Á5 V cm 2 , has been realized by firing a graphite/carbon black composite under an inert atmosphere. Glass frit sealed monolithic test cells have been prepared using this platinum-free material. A solar efficiency of 6% on a 2Á0 cm 2 active cell area has been achieved in this case. Various types of non-volatile imidazolium-based binary ionic liquid electrolytes have been synthesized and optimized with respect to diffusion-limited currents and charge transfer resistances in DSC. In addition, quasi-solid-state electrolytes have been successfully tested by applying inorganic (SiO 2 ) physical gelators. For the use in semi-transparent DSC modules, a polyol process has been developed which resulted in the preparation of screen printed, transparent catalytic platinum layers showing an extremely low charge transfer resistance (0Á25 V cm 2 ).

Dye Solar Cells: Basic and Photon Management Strategies

“…Whilst in the first case the process can be carried out having the photo-electrode already dye sensitized, this is prevented in the last case since the high temperature necessary for the glass frit melting will damage the dye molecules. As reported in the step 4, for this reason dyeing is in this case carried out by fluxing the dye solution (Hinsch et al, 2008). g -Electrolyte injection.…”

“…This second procedure has been introduced by the group of Fraunhofer ISE (Hinsch et al, 2008 (Khelashvili et al, 2006). A less viscous alternative, suitable for brush processing or spin coating, consists of an hexachloroplatinic acid solution in 2-propanol (Gutierrez-Tauste et al, 2005).…”

“…The hole is on end stopped by means of a glass patch. Further possibilities consist in fluxing the electrolyte (Hinsch et al, 2008) or in printing (before the device sealing) a previously gelificated redox mediator (P. Wang et al, 2003).…”

Carbon Nanostructures as Low Cost Counter Electrode for Dye-Sensitized Solar Cells

“…Recently, various carbonaceous materials including graphite, carbon black, and carbon nanotubes have been studied as a low cost replacement for Pt as an electrocatalyst for reduction of I 3  ions (Kay & Gratzel 1996;Burnside et al 2000;Suzuki et al 2003;Murakami et al 2006;Ramasamy et al 2007;Fan et al 2008;Hinsch et al 2008;Joshi et al 2009;Lee et al 2009;Skupien et al 2009;Calandra et al 2010). The carbonaceous materials are plentiful, inexpensive, and also exhibit high resistivity to corrosion (Ramasamy et al 2007).…”

“…The carbonaceous materials are plentiful, inexpensive, and also exhibit high resistivity to corrosion (Ramasamy et al 2007). Replacement of Pt with carbon-based materials can also speed up DSSC commercialization (Burnside et al 2000;Hinsch et al 2008;Han et al 2009;Skupien et al 2009;Joshi et al 2010).…”