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Printable hole‐conductor‐free perovskite solar cells (PSCs) have attracted intensive research attention due to their high stability and simple manufacturing process. However, the cells have suffered severe potential loss in the absence of the hole transporting layer. The dimensionality of the perovskite absorber in the mesoporous carbon electrodes by conducting post‐treatments is reduced. The low‐dimensional perovskites possess wide‐bandgaps and form type‐II band alignment, favoring directional charge transportation and thus enhancing the device performance. For the cells using MAPbI3 (MA = methylammonium) as the light absorber, the open‐circuit voltage (VOC) is significantly enhanced from 0.92 to 0.98 V after posttreatment, delivering an overall efficiency of 16.24%. For the cells based on FAPbI3 (FA = formamadinium), a high efficiency of 17.47% is achieved with VOC of 1.02 V, which are both the highest reported values for printable hole‐conductor‐free PSCs. This strategy provides a facile method for tuning the energy level alignment for mesoscopic perovskite‐based optoelectronics. [ABSTRACT FROM AUTHOR]

The low cost and scalability advantages of printable mesoscopic perovskite solar cells (p‐MPSCs) are impaired by the issue of limited power conversion efficiency (PCE). Herein, the PCE of p‐MPSCs is improved by introducing the polymer additive polyacrylonitrile (PAN) into the formamidinium (FA)‐based perovskite for crystallization and defect modulation. PAN forms hydrogen bond and coordination bond with halide perovskite through its C≡N group. Such interactions improve the crystallization and filling of FA‐based perovskite in the mesoscopic scaffold and bring a long carrier lifetime by passivating defects. The synergy improves the PCE of p‐MPSCs from 16.80% to 18.33%. Meanwhile, the hydrophobic nature of PAN enhances the device's resistance against moisture. This work demonstrates that the polymer additive is a promising choice for breaking the PCE limit of p‐MPSCs. [ABSTRACT FROM AUTHOR]

The anion exchange between MAPbX3 (X = I− or Br−) and MAX salts in a solution environment is investigated. We find that I− can enter MAPbBr3 single crystals (SC) in millimeter scale, while Br− can only penetrate the surface of MAPbI3 SC in a micrometer scale. Due to the lattice variation, the reaction is partially reversible. [ABSTRACT FROM AUTHOR]

High-performance perovskite solar cell processed in ambient air is a big challenge due to the sensitivity of perovskite films to air. Many defects are generated easily at grain boundaries and in the perovskite films by conventional molecular/ion precursor solution mixing methods (i.e., solution mixing-based method), which restrict its stability in air and photovoltaic performance with most power conversion efficiency less than 15%. In this work, we develop a facile method for air-processed, highly crystalline, quasi-3D perovskite film with large grain size (over 6.6 times bigger than that from control conventional method) and improved ambient air stability by phenylethylammonium (PEA)-doped MA1−xPEAxPbI3 perovskite crystal engineering. Furthermore, benefiting from PEA+ doping and crystal engineering, the trap density decreases 50% compared with control. Consequently, with the optimal concentration of PEA doping, the power conversion efficiency increases from 15.6% for conventional solution mixing-based perovskite solar cells to 17.6% for crystal engineering-based ones with significantly improved moisture stability. The perovskite crystal engineering-based solar cells without any encapsulation retain 75% of the initial performance after 30-day storage in ambient air under a relative humidity of 50 ± 10%, and two times faster degradation rate is observed for control, conventional solution mixing-based perovskite solar cells when compared with crystal engineering-based ones. [ABSTRACT FROM AUTHOR]

Background: More than one-fifth of the world's population consumes Chinese cuisines regularly, but no evidence-based healthy diets fitting the Chinese food culture are available for implementation.Methods: A multicenter, patient- and outcome assessor-blind, randomized feeding trial was conducted among 265 participants with 130 to 159 mm Hg baseline systolic blood pressure (SBP) for 4 major Chinese cuisines (Shangdong, Huaiyang, Cantonese, Szechuan). After a 7-day run-in period on a control diet matching the usual local diets, participants were randomized to continue with the control diet or the cuisine-based Chinese heart-healthy diet for another 28 days. The primary outcome was SBP, and secondary outcomes included diastolic blood pressure and food preference score. Linear regression models were used to estimate the intervention effects and adjustments for the center. The incremental cost per 1 mm Hg reduction in SBP was also calculated.Results: A total of 265 participants were randomized (135 on the Chinese heart-healthy diet and 130 on the control diet), with 52% women, mean age of 56.5±9.8 years, and mean SBP and diastolic blood pressure of 139.4±8.3 and 88.1±8.0 mm Hg, respectively, at baseline. The change in SBP and diastolic blood pressure from baseline to the end of the study in the control group was -5.0 (95% CI, -6.5 to -3.5) mm Hg and -2.8 (95% CI, -3.7 to -1.9) mm Hg, respectively. The net difference of change between the 2 groups in SBP and diastolic blood pressure were -10.0 (95% CI, -12.1 to -7.9) mm Hg and -3.8 (95% CI, -5.0 to -2.5) mm Hg, respectively. The effect size did not differ among cuisines (P for interaction=0.173). The mean food preference score was 9.5 (with 10 the best preferred) at baseline, and the net change during intervention was 0.1 (95% CI, -0.1 to 0.2; P=0.558). The incremental cost-effectiveness ratio per 1 mm Hg SBP reduction was CNY 0.4 (USD 0.06) per day. No difference in the number of adverse events was found between the 2 groups (P=0.259), and none of the adverse events was associated with the intervention.Conclusions: The Chinese heart-healthy diet is effective, palatable, and cost-effective in reducing blood pressure in Chinese adults with high blood pressure, with a clinically significant effect applicable across major Chinese cuisine cultures.Registration: URL: https://www.Clinicaltrials: gov; Unique identifier: NCT03882645. [ABSTRACT FROM AUTHOR]

Triple‐mesoscopic perovskite solar cells (PSCs) have attracted intensive attention due to the high stability, simple fabrication process, and low material cost. In this structure, the perovskite layer is hosted by a triple‐mesoscopic scaffold of TiO2/ZrO2/carbon, and thus the crystal quality is sensitive to the thermal annealing process. Typically, the annealing process is conducted in a petri dish, for which the solvent evaporation of the perovskite precursor is slowed down, but not controllable and designable. To control the solvent evaporation, annealing chambers are first designed with different shape and vapor releasing channels. Then, physical simulations are performed by a finite element method, and it is found out that the chamber with a crowned top and releasing channels on the bottom sides can realize homogeneous distribution of the solvent vapor. To verify the simulation results, chambers are fabricated by 3D printing technique, for which the printing deviation can be as low as 100 µm. By balancing the solvent evaporation and release, the optimal solvent evaporation is achieved of the perovskite precursor in the triple‐mesoscopic scaffold. This work offers a method to obtain homogeneous distribution of solvent vapor, and provides a new insight into understanding the influence of solvent evaporation during the thermal annealing process for PSCs. [ABSTRACT FROM AUTHOR]

Few studies have examined young people’s attitudes toward death escape acceptance and its relationship to mindfulness. This study addressed this issue and examined the mediating role of emotion regulation. In Study 1, 61 undergraduate students aged 19–22 years participated in a mindfulness intervention program, and the results showed that increasing young people’s levels of mindfulness could improve their attitudes toward death escape acceptance. The Study 2, which recruited 440 young people aged 18–26 years to complete a cross-sectional survey, replicated the main effect and showed that young people’s difficulty in emotion regulation fully mediated the coping effect of mindfulness. These findings suggest that individuals with high levels of mindfulness may have low levels of difficulty in emotion regulation and in turn promote healthy attitudes toward death escape acceptance. [ABSTRACT FROM AUTHOR]