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A galvanic displacement reaction using zinc powder to reduce Sn4+ in the precursor and enhance the device stability was reported. A record power conversion efficiency of 8.27% was achieved in mesoporous CsSnI3 solar cells.

Like ABX3 halide perovskites, A3YX antiperovskites also have high symmetry and high electronic dimensionality and thus are expected to hold the promise of producing excellent optoelectronic properties. In this work, we explore the optoelectronic-relevant properties of oxyhalide and chalcohalide antiperovskites A3YX through a combination of density functional theory calculations, chemical synthesis, and material characterizations, with a particular focus on bandgap engineering and thermodynamic stability. It is found that the conduction band minimum and valence band maximum of these antiperovskites are contributed mainly by the cations at the octahedral corners and the anions at the octahedral centers, respectively. In contrast, the halogen anions at the cuboctahedral voids contribute little to the band edges. As a result, element substitutions at the octahedral corners and centers can effectively engineer the bandgaps, whereas those at the cuboctahedral voids have limited influence on the bandgap. Further, it is found that the thermodynamic stability of these antiperovskites depends strongly on the constituent ions, e.g., the thermodynamic stability decreases significantly as the Y anion changes from O to S and Se. Our results provide critical insights into the bandgap properties and thermodynamic stability of A3YX oxyhalide and chalcohalide antiperovskites for potential optoelectronic applications.

Since ABX3 halide perovskites exhibit intrinsic instability, their A2BX6 variants have been examined as potential alternatives for optoelectronic applications. The better stability of A2BX6 variant...

Ge-based hybrid perovskite materials have demonstrated great potential for second harmonic generation (SHG) due to the geometry and lone-pair induced non-centrosymmetric structures. Here, we report a new family of hybrid 3D Ge-based bromide perovskites AGeBr

Genome‐wide 5hmC profiling in cell‐free DNA acquired from CRC patients, adenoma patients, and healthy individuals revealed that the differential 5hmC‐modified regions were gathered into four clusters with no overlap, although there are a few overlapped genes shared between the different clusters. CRC patients with adenoma history showed exclusive 5hmC‐gain characteristics, which was consistent with the ‘parallel’ evolution hypothesis in adenoma., Approximately 85% colorectal cancers (CRCs) are thought to evolve through the adenoma‐to‐carcinoma sequence associated with specific molecular alterations, including the 5‐hydroxymethylcytosine (5hmC) signature in circulating cell‐free DNA (cfDNA). To explore colorectal disease progression and evaluate the use of cfDNA as a potential diagnostic factor for CRC screening, here, we performed genome‐wide 5hmC profiling in plasma cfDNA and tissue genomic DNA (gDNA) acquired from 101 samples (63 plasma and 38 tissues), collected from 21 early‐stage CRC patients, 21 AD patients, and 21 healthy controls (HC). The gDNA and cfDNA 5hmC signatures identified in gene bodies and promoter regions in CRC and AD groups were compared with those in HC group. All the differential 5hmC‐modified regions (DhMRs) were gathered into four clusters: Disease‐enriched, AD‐enriched, Disease‐lost, and AD‐lost, with no overlap. AD‐related clusters, AD‐enriched and AD‐lost, displayed the unique 5hmC signals in AD patients. Disease‐enriched and Disease‐lost clusters indicated the general 5hmC changes when colorectal lesions occurred. Cancer patients with a confirmable adenoma history segmentally gathered in AD‐enriched clusters. KEGG functional enrichment and GO analyses determined distinct differential 5hmC‐modified profiles in cfDNA of HC individuals, AD, and CRC patients. All patients had comprehensive 5hmC signatures where Disease‐enriched and Disease‐lost DhMR clusters demonstrated similar epigenetic modifications, while AD‐enriched and AD‐lost DhMR clusters indicated complicated subpopulations in adenoma. Analysis of CRC patients with adenoma history showed exclusive 5hmC‐gain characteristics, consistent with the ‘parallel’ evolution hypothesis in adenoma, either developed through the adenoma‐to‐carcinoma sequence or not. These findings deepen our understanding of colorectal disease and suggest that the 5hmC modifications of different pathological subtypes (cancer patients with or without adenoma history) could be used to screen early‐stage CRC and assess adenoma malignancy with large‐scale follow‐up studies in the future.

Low-dimensional-networked metal halides are attractive for the screening of emitters applied in solid-state lighting and displays, but the lead toxicity and poor stability are obstacles that must be overcome in industrial applications. Herein, we aim at the discovery of bright and stable photoluminescence in zero-dimensional (0D) Mn2+-based metal halides. By manipulation of Cl/Br transmutation, the nature of the halogen can be confirmed as a pivotal factor to tune the PL behaviors, and the optimum Mn2+ emission with a high PLQY of 99.8% and a short lifetime of 0.372 ms can be achieved in (C24H20P)2MnBr4. The thermal quenching behaviors have been discussed in depth, indicating that the synergistic effect of good chemical stability of organic groups, a long Mn⋯Mn distance of 10.447 A and a relatively large activation energy (ΔE = 0.277 eV) provides a platform for achieving excellent thermal stability in (C24H20P)2MnBr4. Moreover, the as-fabricated white LED device with a high luminous efficacy of 118.9 lm W−1 and a wide color gamut of 105.3% National Television System Committee (NTSC) shows that (C24H20P)2MnBr4 can be employed as a desirable narrow-band green emitter for LED displays. This work provides a new understanding of fine tailoring halogens, and proposes a feasible approach to achieving high thermal stability emitters toward the targeted practical applications.

Controlling the carrier polarity and concentration underlies most electronic and optoelectronic devices. However, for the intensively studied lead halide perovskites, the doping tunability is inefficient. In this work, taking CsPbBr

Interlayer electronic coupling in two-dimensional materials enables tunable and emergent properties by stacking engineering. However, it also results in significant evolution of electronic structures and attenuation of excitonic effects in two-dimensional semiconductors as exemplified by quickly degrading excitonic photoluminescence and optical nonlinearities in transition metal dichalcogenides when monolayers are stacked into van der Waals structures. Here we report a van der Waals crystal, niobium oxide dichloride (NbOCl

Metal halide perovskites have received much attention for their application in light-emitting diodes (LEDs) in the past several years. Rapid progress has been made in efficient green, red, and near-infrared perovskite LEDs. However, the development of blue perovskite LEDs is still lagging far behind. Here, we report efficient sky-blue perovskite LEDs by rearranging low-dimensional phase distribution in quasi-2D perovskites. We incorporated sodium ions into the mixed-Cl/Br quasi-2D perovskites with phenylethylammonium as the organic spacer and cesium lead halide as the inorganic framework. The inclusion of the sodium ion was found to significantly reduce the formation of the

Zero-dimensional (0D) Mn2+-based metal halides are potential candidates as narrow-band green emitters, and thus it is critical to provide a structural understanding of the photophysical process. Herein, we propose that a sufficiently long Mn-Mn distance in 0D metal halides enables all Mn2+ centers to emit spontaneously, thereby leading to near-unity photoluminescence quantum yield. Taking lead-free (C10H16N)2Zn1-xMnxBr4 (x = 0-1) solid solution as an example, the Zn/Mn alloying inhibits the concentration quenching that is caused by the energy transfer of Mn2+. (C10H16N)2MnBr4 exhibits highly thermal stable luminescence even up to 150 °C with a narrow-band green emission at 518 nm and a full width at half maximum of 46 nm. The fabricated white light-emitting diode device shows a high luminous efficacy of 120 lm/W and a wide color gamut of 104% National Television System Committee standard, suggesting its potential for liquid crystal displays backlighting. These results provide a guidance for designing new narrow-band green emitters in Mn2+-based metal halides.

Single-atom catalysts (SACs) have attracted significant attention because they exhibit unique catalytic performance due to their ideal structure. However, maintaining atomically dispersed metal under high temperature, while achieving high catalytic activity remains a formidable challenge. In this work, we stabilize single platinum atoms within sub-nanometer surface cavities in well-defined 12CaO·7Al2O3 (C12A7) crystals through theoretical prediction and experimental process. This approach utilizes the interaction of isolated metal anions with the positively charged surface cavities of C12A7, which allows for severe reduction conditions up to 600 °C. The resulting catalyst is stable and highly active toward the selective hydrogenation of nitroarenes with a much higher turnover frequency (up to 25772 h−1) than well-studied Pt-based catalysts. The high activity and selectivity result from the formation of stable trapped single Pt atoms, which leads to heterolytic cleavage of hydrogen molecules in a reaction that involves the nitro group being selectively adsorbed on C12A7 surface., Stabilize the active metal single atoms under harsh conditions is critical for the development of single atom catalysts. Here the authors report a nanoporous crystal, 12CaO·7Al2O3, that can firmly stabilize Pt single atoms in its surface cavities for efficient catalytic hydrogenation of nitroarenes.

Circularly polarized luminescent (CPL) materials are promising in applications such as 3D displays and quantum communication. Hybrid organic-inorganic copper(I) iodides have been rapidly developed due to their intense photoluminescence and structural diversity; nevertheless, the reported Cu-I clusters rarely show CPL activities. In this study, we introduced chiral organic molecules R/S-methylbenzylammonium (R/S-MBA) into Cu-I inorganic skeletons to achieve chiral tetranuclear (R/S-MBA)4Cu4I4 clusters with intense orange luminescence and CPL activity at room temperature. These enantiomeric (R/S-MBA)4Cu4I4 clusters show oppositely signed circular dichroism (CD) signals, which agree well with their simulated electronic CD spectra. The crystallization-induced helical arrangement of (R/S-MBA)4Cu4I4 clusters and their largely distorted polynuclear configuration demonstrate a new platform for the study of chiral-related properties.

Suzuki cross-coupling reactions catalyzed by palladium are powerful tools for the synthesis of functional organic compounds. Excellent catalytic activity and stability require negatively charged Pd species and the avoidance of metal leaching or clustering in a heterogeneous system. Here we report a Pd-based electride material, Y3Pd2, in which active Pd atoms are incorporated in a lattice together with Y. As evidenced from detailed characterization and density functional theory (DFT) calculations, Y3Pd2 realizes negatively charged Pd species, a low work function and a high carrier density, which are expected to be beneficial for the efficient Suzuki coupling reaction of activated aryl halides with various coupling partners under mild conditions. The catalytic activity of Y3Pd2 is ten times higher than that of pure Pd and the activation energy is lower by nearly 35%. The Y3Pd2 intermetallic electride catalyst also exhibited extremely good catalytic stability during long-term coupling reactions., In Suzuki coupling reactions, excellent catalytic performance require negatively charged Pd species and the avoidance of metal leaching or clustering. Here the authors implanted Pd sites into an intermetallic electride, Y3Pd2, which serves as an efficient and stable catalyst for Suzuki coupling reactions.

Zero-dimensional hybrid manganese halides with the type-I band alignment between the manganese halide tetrahedra and organic matrices have attracted much attention as highly efficient narrow-band green emitters. Herein we study the photoluminescence (PL) behavior of hybrid manganese bromides with type-II band alignment, where the lowest unoccupied molecular orbital (LUMO) level can be tuned by employing quaternary phosphonium dications with different degrees of conjugation. For low-conjugated organic matrices, the band alignment can shift from type II in the ground state to type I in the excited state, which enables high photoluminescence quantum yields. In contrast, for high-conjugated organic matrices, the band alignment cannot convert to type I in the excited state because the LUMO lies too low, and thus, the excited electrons are transferred from the tetrahedra to the matrices, which leads to severe PL quenching. Our results show the importance of the excited-state band alignment for understanding the PL behavior of hybrid metal halide semiconductors.

Halide double perovskites A2B(I)B(III)X6, in which monovalent B(I) and trivalent B(III) cations are arranged in the B-sites of the perovskite structure with a rock-salt ordering, have attracted substantial interest in the field of optoelectronics. However, the rock-salt ordering generally leads to low electronic dimensionality, with relatively large bandgaps and large carrier effective masses. In this work, we demonstrate, by density functional theory (DFT) calculations, that the electronic dimensionality and thus the electronic properties of halide double perovskites can be effectively modulated by manipulating the arrangement of the B-site cations. Through symmetry analysis and DFT calculations, we propose a family of halide double perovskites A2B(I)B(II)X5 where the B-site cations adopt a columnar-ordered arrangement. Among the considered compounds, Cs2AgPdCl5, Cs2AgPdBr5, and Cs2AgPtCl5 were successfully synthesized as the first examples of the B-site columnar-ordered halide double perovskites. These compounds exhibit small bandgaps of 1.33-1.77 eV that are suitable for visible light absorption, small carrier effective masses along the octahedra chains, and good thermal and air stability. Our work provides a prototype double perovskite structure to incorporate cations in +1 and +2 oxidation states, which may significantly expand the large family of the halide double perovskites and offer a platform to explore prospective optoelectronic semiconductors.

Lead halide perovskites undergo pressure-induced phase transition, facilitated by bond compressions and different tilt patterns of the ${\mathrm{PbI}}_{6}$ octahedra. Utilizing first-principles calculations we investigated 14 possible tilt systems of ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$ under compression, derived from the high-symmetry $Pm\overline{3}m$ structure. Fr substitution is adopted to mimic the rotational disorder effect of the ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}$ cation with the similar size (at room temperature or higher). Analyses of these phases reveal an interplay between tilting and distortion of the ${\mathrm{PbI}}_{6}$ octahedra. Dynamical fluctuations at finite temperature provide additional insight into the phases' stability. Drawing from the trends observed in $\mathrm{Fr}\mathrm{Pb}{\mathrm{I}}_{3}$ and additional calculations for perovskites involving differently ordered organic cations, we propose that phase transition in ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$ occurs from tetragonal at ambient pressure to orthorhombic under high pressure via the pathway I4/mcm$\ensuremath{\rightarrow}$P4/mbm$\ensuremath{\rightarrow}$Imm2. The distinct discontinuity in the calculated volume-pressure curve of I4/mcm and band-gap evolution of the proposed phases are consistent with photoluminescence shifts observed in ${\mathrm{CH}}_{3}{\mathrm{NH}}_{3}{\mathrm{PbI}}_{3}$ under pressure.

SrTiN2 is expected to exhibit unique carrier transport properties since it has a two-dimensional (2D) electron transport layer in its natural layered crystal structure, and its conduction band mini...

Lead halide perovskites, with high photoluminescence efficiency and narrow-band emission, are promising materials for display and lighting. However, the lead toxicity and environmental sensitivity hinder their potential applications. Herein, a new antimony-doped lead-free inorganic perovskites variant Cs2SnCl6:xSb is designed and synthesized. The perovskite variant Cs2SnCl6:xSb exhibits a broadband orange-red emission, with a photoluminescence quantum yield (PLQY) of 37%. The photoluminescence of Cs2SnCl6:xSb is caused by the ionoluminescence of Sb3+ within Cs2SnCl6 matrix, which is verified by temperature dependent photoluminescence (PL) and PL decay measurements. In addition, the all inorganic structure renders Cs2SnCl6:xSb with excellent thermal and water stability. Finally, a white light-emitting diode (white-LED) is fabricated by assembling Cs2SnCl6:0.59%Sb, Cs2SnCl6:2.75%Bi and Ba2Sr2SiO4: Eu2+ onto the commercial UV LED chips, and the color rendering index (CRI) reaches 81.