Selective Interfacial Excited-State Carrier Dynamics and Efficient Charge Separation in Borophene-Based Heterostructures.

Borophene-based van der Waals heterostructures have demonstrated enormous potential in the realm of optoelectronic and photovoltaic devices, which has sparked a wide range of interest. However, a thorough understanding of the microscopic excited-state electronic dynamics at interfaces is lacking, which is essential for determining the macroscopic optoelectronic and photovoltaic performance of borophene-based devices. In this study, photoexcited carrier dynamics of ß12 , χ3 , and α΄ borophene/MoS2 heterostructures are systematically studied based on time-domain nonadiabatic molecular dynamics simulations. Different Schottky contacts are found in borophene/semiconductor heterostructures. The interplay between Schottky barriers, electronic coupling, and the involvement of different phonon modes collectively contribute to the unique carrier dynamics in borophene-based heterostructures. The diverse borophene allotropes within the heterostructures exhibit distinct and selective carrier transfer behaviors on an ultrafast timescale: electrons tunnel into α΄ borophene with an ultrafast transfer rate (≈29 fs) in α΄/MoS2 heterostructures, whereas ß12 borophene only allows holes to migrate with a lifetime of 176 fs. The feature enables efficient charge separation and offers promising avenues for applications in optoelectronic and photovoltaic devices. This study provides insight into the interfacial carrier dynamics in borophene-based heterostructures, which is helpful in further design of advanced 2D boron-based optoelectronic and photovoltaic devices.

A repository for the publication and sharing of heterogeneous materials data.

National Materials Data Management and Service platform (NMDMS) is a materials data repository for the publication and sharing of heterogeneous materials scientific data and follows the FAIR principles: Findable, Accessible, Interoperable, and Reusable. To ensure data are 'Interoperable, NMDMS uses a user-friendly semi-structured scientific data model, named dynamic container', to define, exchange, and store heterogeneous scientific data. Then, a personalized yet standardized data submission subsystem, a rigorous project data review and publication subsystem, and a multi-granularity data query and retrieval subsystem collaboratively make data 'Reusable', 'Findable', and 'Accessible'. Finally, China's "National Key R&D Program: Material Genetic Engineering Key Special Project" has adopted NMDMS to publish and share its project data. There are 12,251,040 pieces of data published in NMDMS since 2018, under 87 categories and 1,912 user-defined schemas from 45 projects. The platform has been accessed 908875 times, and 2403,208 pieces of data have been downloaded. In short, NMDMS effectively accelerates the publication and sharing of material project data in China.

Substrate-Mediated Borophane Polymorphs through Hydrogenation of Two-Dimensional Boron Sheets.

The two-dimensional boron monolayer (borophene) stands out from the two-dimensional atomic layered materials due to its structural flexibility and tunable electronic and mechanical properties from a large number of allotropic materials. The stability of pristine borophene polymorphs could possibly be improved via hydrogenation with atomic hydrogen (referred to as borophane). However, the precise adsorption structures and the underlying mechanism are still elusive. Employing first-principles calculations, we demonstrate the optimal configurations of freestanding borophanes and the ones grown on metallic substrates. For freestanding borophenes, the energetically favored hydrogen adsorption sites are sensitive to the polymorphs and corresponding coordination numbers of boron atoms. With various metal substrates, the hydrogenation configurations of borophenes are modulated significantly, attributed to the overlap between B pz and H s orbitals. These findings provide a deep insight into the hydrogenating borophenes and facilitate the stabilization of two-dimensional boron polymorphs by engineering hydrogen adsorption sites and concentrations.

Neural network training method for materials science based on multi-source databases.

The fourth paradigm of science has achieved great success in material discovery and it highlights the sharing and interoperability of data. However, most material data are scattered among various research institutions, and a big data transmission will consume significant bandwidth and tremendous time. At the meanwhile, some data owners prefer to protect the data and keep their initiative in the cooperation. This dilemma gradually leads to the "data island" problem, especially in material science. To attack the problem and make full use of the material data, we propose a new strategy of neural network training based on multi-source databases. In the whole training process, only model parameters are exchanged and no any external access or connection to the local databases. We demonstrate its validity by training a model characterizing material structure and its corresponding formation energy, based on two and four local databases, respectively. The results show that the obtained model accuracy trained by this method is almost the same to that obtained from a single database combining all the local ones. Moreover, different communication frequencies between the client and server are also studied to improve the model training efficiency, and an optimal frequency is recommended.

Association between CD14 gene promoter polymorphisms with serum total-IgE and eosinophil levels in atopic and non-atopic asthma patients in a Chinese Han population.

OBJECTIVE: The aim of this study was to investigate the association between CD14 gene promoter SNPs with serum total-IgE and eosinophil levels in atopic asthma and non-atopic asthma in Chinese Han. METHODS: A total of 152 patients with asthma were divided into atopic asthma (n = 100) and non-atopic asthma (n = 52) groups for this study. Six CD14 gene SNPs were analyzed using PCR and gene sequencing. Serum total-IgE and eosinophil levels were measured. The association between genotype frequencies of the CD14 gene loci with total-IgE and eosinophil levels in atopic asthma and non-atopic asthma was evaluated by the ANOVA test method. Hundred and sixteen healthy subjects constitute the control group. RESULTS: We found that serum total-IgE and eosinophil levels were significantly higher in individuals with atopic asthma when compared to individuals with non-atopic asthma (p < 0.01). For non-atopic asthma, the total-IgE levels of the heterozygous genotypes were significantly higher than the corresponding levels for the homozygous genotypes in CD14-260C > T, CD-651C > T, CD-911A > C and CD-1247A > G (p < 0.01). In atopic asthma, there was no statistical significance for either serum total-IgE or eosinophil levels among the genotypes of the CD14 gene SNPs. In addition, allele A frequency of CD14-1247A > G was significantly different between the atopic asthma and non-atopic asthma groups (p = 0.025). CONCLUSIONS: There was a statistical association between the serum total-IgE level and the CD14 gene promoter SNPs in the non-atopic asthma group. The eosinophil level was not found to be statistically associated with the CD14 gene promoter SNPs in either the atopic asthma or non-atopic asthma groups.