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International audience; Unsatisfactory crystal quality and deep-level defects are detrimental for Cu(In,Ga)(S,Se)2 (CIGSSe) solar cells. In this work, an in-suit K doping strategy is implemented by introducing KF into the CIGSSe precursor solution to promote crystallization and passivate the deep defects. The effects of K on the solution-processed CIGSSe devices are systematic investigated. It has been discovered that K incorporation results in better crystallization, modified CIGSSe surface and fewer detrimental defects. Benefit from the reduction of the band-tailing effects, suppressed defects density and passivated interface recombination, the solution-processed CIGSSe solar cell achieve systematic improvement in open-circuit voltage and fill factor, enabling a champion efficiency of 16.02%, which is the highest value for alkali metal doped CIGSSe solar cells fabricated by solution-processed method. The effective in-suit K doping tactic opens an avenue for developing highly efficient solution-processed CIGSSe solar cells.

Poly(vinylidene fluoride) (PVDF) membrane is easily fouled due to its hydrophobic nature. This study attempted to reduce fouling by combining PVDF with hydrophilic poly(methyl vinyl ether-alt-maleic anhydride) (PVMVE-alt-MA) and TiO2 nanoparticles by phase inversion method. Results showed that the average pore size of the blended membranes increased when the amount of PVME-alt-MA that was added to the casted dope was increased from 0% to 3%, but beyond 3% there was no change in pore size. The membrane made from 6% PVME-alt-MA displayed minimal macrovoid formation, and sustained the highest flux in both pure water crossflow filtration and 1% bovine serum albumin (BSA) laboratory-scale filtration. It also exhibited the highest flux recovery after water rinsing and UV treatment. Flux and transmembrane pressure (TMP) trends indicate that membrane morphology (pore size and sub-layer pore arrangement) have greater impact on preventing cake layer formation than hydrophilicity. Water rinsing caused the membranes to recover 50–95% of their initial flux, whereas UV treatment had minimal effect. The membranes exhibited Reactive Black 5 (RB5) dye removal by photocatalysis.