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The design and facile fabrication of highly efficient, cost-effective and earth abundant counter electrode material on an electrode surface is highly desirable for the application of dye-sensitized solar cells (DSSCs). Herein, using a N,N-dimethylformamide based solution process, transition metal chalcogenide Ni x S y films have been obtained by spin-coating a NiCl 2 -thiourea (Ni-Tu) solution combining mild thermal treatment. XRD, SEM and TEM characterizations reveal that the current procedure allows for phase composition (Ni 3 S 2 , NiS and NiS-NiS 2 ), crystallinity, morphology (film uniformity and compactness) control of the films through simple adjusting Ni/S ratio in the precursor solution. Electrochemical analysis indicates that the FTO supported Ni 3 S 2 and NiS films exhibit excellent electrocatalytic activity toward the reduction of triiodide, resulting in higher photo-electric conversion efficiencies of 6.86% and 6.95% when used as counter electrode in DSSCs, versus 6.66% for Pt. In particular, even without the support of conductive FTO layer, Hall effect measurements and electrocatalytic analysis reveal that pristine Ni x S y films exhibit good electrical conductivity and electrocatalytic activity, yielding a highest photo-electric conversion efficiency of 4.41% when used as counter electrode in DSSCs. Our study thus provides a facile procedure which allows for composition, morphology optimization and high performance for low-cost, large-scale DSSC application. [ABSTRACT FROM AUTHOR]

A novel three-dimensional tetracoordinated organoboron acceptor bearing C^N^C chelate was developed by the direct borylation of pyridine derivatives. Donor-acceptor type emitter based on this novel organoboron acceptor exhibited good stability, high photoluminescence quantum yield (PLQY) and thermally activated delayed fluorescence (TADF) character. By selecting different donors with different electron donating abilities, two distinct electroluminescence devices with white and green emission achieved maximum external quantum efficiency of over 10%. • A novel tetracoordinated organoboron acceptor bearing C^N^C chelate. • Donor-acceptor type emitter based on this acceptor exhibited thermally activated delayed fluorescence. • White and green EL devices with maximum external quantum efficiency of over 10%. [ABSTRACT FROM AUTHOR]

Happiness is an important goal humans pursue. Previous studies found that generalized trust leads to greater well-being. To confirm the universality of previous findings, we conducted two studies using a sample of 69,578 participants from 48 countries to explore the relationship between different types of trust on well-being and the moderating effect of individualism on this relationship. In our Hierarchical Linear Models, all types of trust positively predicted well-being at the individual level, and the effects of trust on well-being were enhanced by country-level individualism. An explanation for this phenomenon is that social trust in collectivist societies mainly originates from conformity to social norms rather than personal preferences as in individualist societies. Findings of this study suggest that different types of social trust contribute to well-being in both individualist and collectivist societies. The well-being benefits of social trust can be enhanced if individuals have autonomy in determining the level of trust and the width of the trust circle. • All types of social trust positively predicted individual level well-being. • National culture conditions the effects of personal contributors of well-being. • Social trust more strongly associated with well-being in individualistic cultures. • The well-being benefits of social trust may be enhanced by individual autonomy. [ABSTRACT FROM AUTHOR]