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Titanium dioxide (TiO 2 ) with dispersed W-doping shows its capability for efficient electron collection from perovskite to TiO 2 in perovskite solar cell. The conduction band (CB) of TiO 2 moves downward (positive shift) with increasing the tungsten (W) content, which enlarges the energy gap between the CB of TiO 2 and the perovskite. Thus, the efficiency of electron injection from perovskite to TiO 2 is increased. Due to the increased electron injection, W-doped TiO 2 (≤0.2% W content) enhances the short-circuit photocurrent (J sc ) of perovskite solar cell and improves the performance of perovskite solar cell. Perovskite solar cell with 0.1% W-doped photoanode obtains the highest power conversion efficiency (η = 10.6%), which shows enhancement by 13% in J sc and by 17% in η, as compared with the undoped TiO 2 perovskite solar cell. [ABSTRACT FROM AUTHOR]

Perovskite solar cells as a hot research topic show the necessity of controlling the interface. In this work, an insulating alkyl chain layer is self-assembled at the perovskite/hole transport material interface, which successfully exhibits a dual function: blocking electron recombination and resisting moisture at the same time. Improved solar energy conversion efficiency and stability of the device are both achieved. [ABSTRACT FROM AUTHOR]

• Vertical zone refining method was applied to produce 7 N-grade indium. • Physical fields during multipass vertical zone refining were simulated by finite volume method. • Voller-Beckerman model was introduced to deal with both back-diffusion and coarsening effect on solute microsegregation. • Dynamical interaction between melt flow and solute redistribution was discussed. • A high-efficiency refining routine for indium was suggested and experimentally proved. Horizontal zone refining has been widely used for the production of ultra-pure metals through solidification-induced microsegregation effect. Current research on vertical zone refining is limited, owing to the high-temperature cracking risk of crucible; however, it is highly potential for low-melting metals as demonstrated in this research. The present work comprehensively dealt with both back-diffusion and coarsening effect on the solute redistribution by adopting the Voller-Beckerman (V-B) model. Physical fields, including temperature, melt flow and solute distribution, were numerically simulated based on In–1 wt.%Sn binary alloy by means of finite volume method, and the dynamic interaction between melt-flow and solute distribution was clarified. A high-efficiency processing routine was suggested, and it was experimentally proved that the vertical zone refining was a promising method for producing ultra-pure 7 N-grade indium. [ABSTRACT FROM AUTHOR]