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Broadband near‐infrared (NIR) phosphors have recently received considerable attention in spectroscopy technology fields, but designing inexpensive, emission peaks centered above 800 nm, and multimodal broadband NIR luminescence material still remains a great challenge. Here, by selecting stannate compound Mg2SnO4 (MSO) as the host, a kind of broadband NIR phosphor MSO:Cr3+ with multimode luminescence properties is reported. The designed material exhibits an emission peaking at 800 nm and a full‐width at half maximum of 180 nm (≈2730 cm−1). The site occupation of Cr3+ in MSO is unraveled by density functional theory calculation. The constructed NIR light‐emitting device based on MSO:Cr3+ displays a high NIR output power of 187.19 mW@100 mA and remarkable photoelectric efficiency of 13.67%, and its multifunctional applications in information encryption, non‐destructive detection, and so on are also demonstrated. Additionally, through defect site reconstruction, MSO:Cr3+ presents superior broadband NIR persistent luminescence (PersL) properties with PersL duration time longer than 50 h. This work provides a feasible strategy to develop intelligent optical material integrated with multimodal luminescence through low‐cost stannate compounds as the host toward versatile applications such as non‐destructive detection and bioimaging. [ABSTRACT FROM AUTHOR]

Spinel configuration is a kind of broadly considered host candidate when designing persistent luminescence (PersL) materials due to the easy generation of vacancies and anti‐site defects. Here, a new strategy of defect enrichment for the activation of PersL is proposed, and in contrast to the spinel configuration, it is demonstrated that the crystal structure of near inverse spinel ensures more numerous defects to activate the near‐infrared (NIR) PersL of Fe3+. Fe3+‐doped MgGa2O4 displays the PersL band in the range of 600 to 900 nm and possesses a super‐long PersL duration time >15 h. The optical analysis and the calculation of density functional theory unravel that the near inverse spinel structure can lower the carrier transfer barriers to accelerate the formation of carrier trap states within the bandgap. Therefore, more numerous defects in this structure may participate in the trapping and de‐trapping process by comparison with the normal spinel configuration. These findings are expected to accelerate the development of new PersL materials through Fe3+ doping toward versatile biological applications in NIR window. [ABSTRACT FROM AUTHOR]

Spinel configuration is a kind of broadly considered host candidate when designing persistent luminescence (PersL) materials due to the easy generation of vacancies and anti‐site defects. Here, a new strategy of defect enrichment for the activation of PersL is proposed, and in contrast to the spinel configuration, it is demonstrated that the crystal structure of near inverse spinel ensures more numerous defects to activate the near‐infrared (NIR) PersL of Fe3+. Fe3+‐doped MgGa2O4 displays the PersL band in the range of 600 to 900 nm and possesses a super‐long PersL duration time >15 h. The optical analysis and the calculation of density functional theory unravel that the near inverse spinel structure can lower the carrier transfer barriers to accelerate the formation of carrier trap states within the bandgap. Therefore, more numerous defects in this structure may participate in the trapping and de‐trapping process by comparison with the normal spinel configuration. These findings are expected to accelerate the development of new PersL materials through Fe3+ doping toward versatile biological applications in NIR window. [ABSTRACT FROM AUTHOR]

Nitrogen/tetrafluoromethane (N 2 /C F 4) has attracted wide attention for its reliable dielectric performance and potential to be utilized as a coolant and insulator of power apparatus. Several studies have investigated the basic properties of N 2 /C F 4 , but dielectric responses of such a mixture under extreme electric fields are not fully understood, primarily on a molecular level. Here, we modeled the N 2 /C F 4 complex and calculated the molecular properties under different external electric fields through computational quantum chemistry methods. Results suggest that the electric-field-induced polarization can be apparently observed in both positive and negative direction cases; the deformed electronic structure leads to an increased dipole moment and a narrowed energy gap. In addition, the molecular vibrational modes are sensitive to external electric fields, resulting in the splitting and shifting of IR spectra. Moreover, the external electric field also affects the excited-state properties of N 2 /C F 4 , and the emerged absorption peaks under extreme electric fields were analyzed in detail. These findings provide a better understanding of the N 2 /C F 4 properties under external electric fields and lay a foundation for designing the electrical insulation systems of the power apparatus. [Display omitted] • The N 2 /C F 4 complex responses to external electric fields were investigated. • The external electric field induces a polarization of the electronic structure of N 2 /C F 4. • The molecular vibrational modes of N 2 /C F 4 are sensitive to external electric fields. • The electronic absorption peaks appearing under extreme electric fields were analyzed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Carbon crystalline phase engineering significantly enhanced the dipole polarization. • The enhancement of the interfacial effect was investigated using first principles. • The impact of the Fe-C interface is confirmed through software simulation. • The corrosion resistance of iron nanowires was enhanced by carbon shells. The study of designing and developing ferromagnetic nanocomposites with both microwave absorption (MA) and corrosion protection properties through microscopic heterogeneous interfacial engineering and crystal phase engineering remains challenging. In this study, Fe@C core–shell nanowires (FCNWs) are obtained by magnetic field-controlled in situ reduction method and annealing process to de-regulate the carbon shell thickness and carbon morphology. The enhancement of Fe-C heterogeneous relative interfacial effects and dielectric/magnetic response is revealed using density functional theory and simulated electromagnetic field distribution, and the modulation of the amorphous carbon/graphitic carbon ratio achieves the enhancement of dipole polarization in the low-frequency region. The FCNWs absorber had a minimum reflection loss (RL min) of −47.6 dB at a thickness of 4.9 mm, and the maximum effective absorption bandwidth (EAB max) was achieved at 5.5 mm up to 4.0 GHz. In addition, the shielding effect of the graphitic carbon shell on the corrosion medium and the addition of additional electron conduction pathways allow the FCNWs absorber to obtain smaller corrosion currents and larger polarization resistances compared to Fe nanowires. Thus, modulation of atomic-scale heterogeneous interfaces and crystal phases has great potential in modulating the dielectric response. [ABSTRACT FROM AUTHOR]