A simple yet general swelling-deswelling microencapsulation strategy has been developed to achieve well dispersed and intimately passivated crystalline organic-inorganic perovskites nanoparticles within polymer matrixes and results in a series of highly luminescent CH NH PbBr (MAPbBr )-polymer composite films with unprecedented water and thermal stabilities and superior color purity.

Controlling the dopant type, number, and position in doped metal nanoclusters (nanoparticles) is crucial but challenging. In the work described herein, we successfully achieved the mono-cadmium doping of Au25 nanoclusters, and revealed using X-ray crystallography in combination with theoretical calculations that one of the inner-shell gold atoms of Au25 was replaced by a Cd atom. The doping mode is distinctly different from that of mono-mercury doping, where one of the outer-shell Au atoms was replaced by a Hg atom. Au24Cd is readily transformed to Au24Hg, while the reverse (transformation from Au24Hg to Au24Cd) is forbidden under the investigated conditions.

The structural features that render gold nanoclusters intrinsically fluorescent are currently not well understood. To address this issue, highly fluorescent gold nanoclusters have to be synthesized, and their structures must be determined. We herein report the synthesis of three fluorescent Au24 (SR)20 nanoclusters (R=C2 H4 Ph, CH2 Ph, or CH2 C6 H4 (t) Bu). According to UV/Vis/NIR, differential pulse voltammetry (DPV), and X-ray absorption fine structure (XAFS) analysis, these three nanoclusters adopt similar structures that feature a bi-tetrahedral Au8 kernel protected by four tetrameric Au4 (SR)5 motifs. At least two structural features are responsible for the unusual fluorescence of the Au24 (SR)20 nanoclusters: Two pairs of interlocked Au4 (SR)5 staples reduce the vibration loss, and the interactions between the kernel and the thiolate motifs enhance electron transfer from the ligand to the kernel moiety through the Au-S bonds, thereby enhancing the fluorescence. This work provides some clarification of the structure-fluorescence relationship of such clusters.

Metal halide perovskite solar cells (PSCs) have seen an extremely rapid rise in power conversion efficiencies in the past few years. However, the commercialization of this class of emerging materials still faces serious challenges, one of which is the instability against external stimuli such as moisture, heat, and irradiation. Much focus has deservedly been placed on understanding the different origins of intrinsic instability and thereby enhancing their stability. Among these, tensile strain in perovskite films is an important source of instability that cannot be overcome using conventionally extrinsic stabilization approaches such as encapsulation. Here we review recent progress in understanding of the origin of strain in perovskites as well as its corresponding characterization methods, and their impacts on the physical properties of perovskites and the performance of PSCs including efficiency and stability. We then summarize the latest advances in strain-regulation strategies that improve the intrinsic stability of perovskites and photovoltaic devices. Finally, we provide a perspective on how to make further progress in stable and high-efficiency PSCs via strain engineering.

Doped nanoparticles (especially bimetal doped nanoparticles) have attracted extensive interest not only for fundamental scientific research but also for application purposes. However, their indefinite composition (structure) and broad distribution hinder an insightful understanding of the interaction between these invasive metals in bimetal doped nanoparticles. Fortunately, atom-precise bimetal doped ultrasmall nanoparticles (nanoclusters) provide opportunities to obtain such insights. However, atom-precise trimetal nanoclusters and their structures have rarely been reported. Here, we successfully dope thiolated Au 25 nanoclusters with Hg and Ag successively by using a biantigalvanic reduction method. We then fully characterize the as-obtained trimetal nanoclusters using multiple techniques (including single-crystal X-ray crystallography), and we demonstrate that the mercury and silver dopings exhibit not only a synergistic but also a counteractive influence on some of the physicochemical properties of Au 25 .

Aiming to overcome both the structural and commercial limitations of flexible thermoelectric power generators, an efficient room‐temperature aqueous selenization reaction that can be completed in air within less than 1 min, to directly fabricate thin β‐Ag2Se films consisting of perfectly crystalline and large columnar grains with both in‐plane randomness and out‐of‐plane [201] preferred orientation, is designed. A high power factor (PF) of 2590 ± 414 µW m−1 K−2 and a figure‐of‐merit (zT) of 1.2 ± 0.42 are obtained from a sample with a thickness of ≈1 µm. The maximum output power density of the best 4‐leg thermoelectric generator sample reach 27.6 ± 1.95 and 124 ± 8.78 W m−2 at room temperature with 30 and 60 K temperature differences, respectively, which may be useful in future flexible thermoelectric devices.

The tribovoltaic effect can generate direct-current (DC) by the friction between semiconductor heterojunction, which has arisen worldwide attentions recently. However, the low output voltage and power have been restricting the...

Herein, we describe how to utilize stacking interactions to achieve selective supramolecular transformation and molecular Borromean rings (BRs). By using a dinuclear naphthalenediimide (NDI)-based Cp*Rh acceptor and linear bipyridyl ligands, organometallic rectangles featuring dynamic behavior have been constructed. Unique discrete aromatic stacking arrays were formed by inducing pyrene units as guest molecules. The topology of the BRs was realized by the use of a strategically chosen ligand which was capable of participating in D−A interactions and hydrogen bonding, as evidenced from single-crystal X-ray analysis and computational studies. These self-assembly processes underline the advantages of dynamic bonding and π−π stacking interactions, and serve to illustrate a new approach to generating structurally and topologically nontrivial supramolecular architectures.