Thin Film Nano Solar Cells—From Device Optimization to Upscaling

Abstract

Stainless steel based dye solar cells have been upscaled from small, laboratory size test cells of 0.32 cm2 active area to 6 cm x 6 cm "mini-modules" with active areas ca. 15 cm2. Stainless steel works as the photoelectrode substrate whilst the counter electrode is prepared on indium-doped tin oxide coated polyethyleneterephtalate or polyethylenenaphtalate plastic foil (fluorine-doped tin oxide coated glass as a reference). Additional current collector structures were deposited on the counter electrode substrate with inkjet-printing of silver nanoparticle ink in order to reduce the lateral resistance of the plastic foil. Flexible substrates enable roll-to-roll type industrial manufacturing of the cells and the steel's superior conductivity compared to the typical substrate materials such as glass and plastic makes it possible to prepare even substantially larger modules. The best efficiencies obtained this far with the "mini-module" using a stainless steel photoelectrode are 2.5% with a platinum-sputtered indium-doped tin oxide coated polyethyleneterephtalate counter electrode and 3.4% with a thermally platinized fluorine-doped tin oxide coated glass counter electrode. These efficiencies are on the same level than those measured with small cells prepared with similar methods and materials (3.4%-4.7%, depending on configuration, which are amongst the highest reported for this kind of a dye solar cell). Replacing expensive conducting glass with steel and plastic foils as the substrate materials leads also to economical savings in the cell production.

Two-Dimensional Time-Dependent Numerical Modeling of Edge Effects in Dye Solar Cells

“…In the absence of a well established physical model for non-ideal electron transport, we use eq. (39) in the present work.…”

“…Hence if the model is expanded to 3D the sheet resistance and dierent current collector structures can be easily added as separate modeling domain. The model for the current collection is shown in our previous work [39].…”

Device Physics of Dye Solar Cells

“…The total substrate resistance R TCO depends on the cell geometry and needs to be minimized to obtain high fi ll factors. Optimization of current collection becomes increasingly more important with large cells and modules, [ 99 ] but it can also signifi cantly affect the conversion effi ciency of small single cells.…”

Effect of molecular filtering and electrolyte composition on the spatial variation in performance of dye solar cells

“…5 The dimensions of the segmented cells used in this study are roughly similar to a single stripe of a DSC mini module such as the ones used in our previous study. 6 In addition to detecting the spatial variation in the photovoltaic performance with segmentation, Raman and incident-photon-to-currentefficiency (IPCE) measurements are executed to further investigate the underlying causes of the performance variation.…”