mesoporous stack-titania (m-TiO 2 ), zirconia (ZrO 2 ), carbon (C)-is printable, C-PSCs are ideal for large scale production and, interestingly, some features that prevent degradation, i.e., lack of metal cathode [9] and organic HTM, [10] are also responsible for the simpler manufacturing process, paving the way for C-PSCs to move quickly from the lab to the market. This module architecture not only uses low-cost materials but can be produced by equipment that has a very low-capital cost thus reducing the barrier to commercialization of perovskite modules. Constraining the grain growth of the perovskite completely within the three mesoporous structures enables crystallization of the perovskite over large areas without the need for dynamic drying [11,12] to mimic the spin coating process. [13] There have been some reports demonstrating that C-PSC modules can be produced by screen printing, via registration of the overlapping layers, and can deliver between 10 and 11% power conversion efficiency (PCE) on 10 × 10 cm 2 substrates, with active areas ranging from 47.6 [7,14] to 70 cm 2 , [15] and, in particular, showing over 1 year stability under illumination, as reported by Grancini et al. [7] These results for C-PSC modules are even more remarkable, considering that modules with comparable active areas (>45 cm 2 ) and different device architecture, yielded respectively 12.6% PCE on 50.6 cm 2 (FTO/c-TiO 2 /graphene+m-TiO 2 / GO-Li/perovskite/spiro-OMeTAD/Au), [16] 8.7% PCE on 60 cm 2 (ITO/PEDOT:PSS/perovskite/PCBM/Au), [17] and 4.3% PCE on 100 cm 2 (FTO/c-TiO 2 /m-TiO 2 /perovskite/spiro-OMeTAD/ Au) [11] ; moreover, the record for PSC modules overall is Microquanta's 16% PCE [18,19] on just 16.29 cm 2 aperture area (active area + dead area for interconnections).Upscaling C-PSC manufacture from 10 × 10 cm 2 to larger substrate dimensions, e.g., A4 size as in our case, is far from trivial. Spraying the TiO 2 blocking layer (BL) at temperatures as high as 300 °C causes the large substrates to crack in the worst case or to bend, compromising the thickness homogeneity over the substrate of the printed layers, mostly and more crucially for the thinnest of the three, the sub-micrometric m-TiO 2 . Any change in the layers' thickness across the substrate can affect the performance of individual cells constituting the module Perovskite solar cells based on an all printable mesoporous stack, made of overlapping titania, zirconia, and carbon layers, represent a promising device architecture for both simple, low-cost manufacture, and outstanding stability. Here a breakthrough in the upscaling of this technology is reported: Screen printed modules on A4 sized conductive glass substrates, delivering power conversion efficiency (PCE) ranging from 3 to 5% at 1 sun on an unprecedented 198 cm 2 active area. An increase in the PCE, due to higher V OC and fill factor, is demonstrated by patterning the TiO 2 blocking layer. Furthermore, an unexpected increase of the performance is observed over time, while storing the modules in the dark,...

Functional expression of lipase B from Pseudozyma antarctica (PalB) in the cytoplasm of Escherichia coli BL21(DE3) and its mutant derivative Origami B(DE3) was explored. Coexpression of DsbA was found to be effective in enhancing PalB expression. The improvement was particularly pronounced with Origami B(DE3) as a host, suggesting that both folding and disulfide bond formation may be major factors limiting PalB expression. Fusion tag technique was also explored by constructing several PalB fusions for the evaluation of their expression performance. While the solubility was enhanced for most PalB fusions, only the DsbA tag was effective in boosting PalB activity, possibly by both enhanced solubility and correct disulfide bond formation. Our results suggest that PalB activity is closely associated with correct disulfide bond formation, and increased solubilization by PalB fusions does not necessarily result in activity enhancement.

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Mesoporous TiO2 films are employed in solar cells, lithium ion batteries, and air and water purification systems, to name a few applications. Film fabrication via coating the substrate with an organic suspension or paste carrying TiO2 nanoparticles is a common method. To lessen the adverse environmental impact, use of water as a solvent and nontoxic chemicals is being preferred over commonly used organic components. In this research, a water-based, nano-TiO2 printable paste formulation with polyethylene glycol (MW 20 000) and propylene glycol was developed and seamlessly interfaced with TiO2 aqueous synthesis for sustainable manufacturing. The innovative combination of propylene glycol and polyethylene glycol is demonstrated to lead to improved paste rheology and sintered film properties. Dye-sensitized solar cells were assembled from the screen-printed films, and the effect of film surface area and porosity on photovoltaic performance was studied. The new aqueous-based paste yielded comparable power conversion efficiency to benchmark organic-based paste made of α-terpineol, ethyl cellulose, and ethanol, opening the avenue for lower cost, green fabrication of mesoporous thin film electrodes.