Reticulated Mesoporous TiO₂ Scaffold, Fabricated by Spray Coating, for Large‐Area Perovskite Solar Cells

Abstract

Development of reproducible, low‐cost fabrication technologies that are readily adaptable to large‐scale production, is one of the main challenges in the field of perovskite solar cells (PSCs). So far, for all the other layers in a solar cell, large‐area deposition methods have been adapted, except for mesoporous fabrication. Herein, the fabrication of mesoporous TiO2 scaffolds using a large‐area deposition technique, such as spray coating, is shown. Moreover, this technique induces the formation of a very specific reticulated structure with well‐delimited, oval‐shaped cavities. The cavities have irregular dimensions, with diameters in the range of 3–7 μm, ≈350 nm height, resulting in an overall increase in roughness of one order of magnitude, compared with the spin‐coated mesoporous scaffold. Using this rough structured mesoporous TiO2 in PSCs not only does not affect the efficiency of solar cells but actually improves it from an average of 10% to 12% in comparison with the devices containing a spin‐coated mesoporous scaffold.

In SituStudy of Order Formation in Mesoporous Titania Thin Films Templated by a Diblock Copolymer during Slot-Die Printing

“…20 The authors found that FCC packing was more stable for spherical micelles with a large core and a thin shell, while BCC favorably occurred at an inverted chain architecture. 20 To date, on the basis of the sol−gel technique, various solution-processing deposition methods were applied for fabricating titania films, such as spin coating, 21 spray coating, 22 inkjet printing, 23 doctor blading 24 and slot-die printing. 25 Among these preparation techniques, slot-die printing has attracted special interest recently because it is an industrial scale technique and allows for simple production of films on most substrates at low cost.…”

Doping in Semiconductor Oxides‐Based Electron Transport Materials for Perovskite Solar Cells Application

“…As a result, the device achieved a PCE of 17.2%. In 2019, Tomulescu et al [ 66 ] compared the preparation process of the TiO 2 mesoporous layer by spin coating and a simple spray, as shown in Figure 2e. Their results indicated that TiO 2 could form a mesoporous structure with excellent network and crystallinity by the spray coating, which significantly increases the roughness and obtain a thinner mesoporous layer, resulting in the reduced loss of charge in the mesoporous layer.…”

Tailoring Ordered Mesoporous Titania Films via Introducing Germanium Nanocrystals for Enhanced Electron Transfer Photoanodes for Photovoltaic Applications

“…[22] To date, so-called diblock-copolymer (DBC)-assisted sol-gel synthesis has proven to be a favorable route to establish titania nanostructures in a controlled fashion. [24,25] The general solgel approach provides a facile solution deposition route that is readily compatible with a variety of film deposition processes ranging from laboratory-scale coating like spin coating [26] to industrial-scale coating like spray coating [27] and slot-die printing. [25] Sol-gel methods also facilitate the dopant incorporation and the resulting doped-films can possess uniform morphology with continuous and pinhole-free structures.…”