Interfacial interaction and intense interfacial ultraviolet light emission at an incoherent interface

Abstract

Incoherent interfaces with large mismatches usually exhibit very weak interfacial interactions so that they rarely generate intriguing interfacial properties. Here we demonstrate unexpected strong interfacial interactions at the incoherent AlN/Al2O3 (0001) interface with a large mismatch by combining transmission electron microscopy, first-principles calculations, and cathodoluminescence spectroscopy. It is revealed that strong interfacial interactions have significantly tailored the interfacial atomic structure and electronic properties. Misfit dislocation networks and stacking faults are formed at this interface, which is rarely observed at other incoherent interfaces. The band gap of the interface reduces significantly to ~ 3.9 eV due to the competition between the elongated Al-N and Al-O bonds across the interface. Thus this incoherent interface can generate a very strong interfacial ultraviolet light emission. Our findings suggest that incoherent interfaces can exhibit strong interfacial interactions and unique interfacial properties, thereby opening an avenue for the development of related heterojunction materials and devices.

Asymmetric Chemical Potential Activated Nanointerfacial Electric Field for Efficient Vanadium Redox Flow Batteries

“…More essentially, in the case of a thermodynamically governed epitaxial growth process, steady-state interfacial reconstruction (white dotted arrows in Figure 2j-k) occurs at atomic-scale N− Mo−C binding region, which may endow these interfaces with distinctive electronic properties. 21 Additionally, the calculated lattice mismatch (detailed in the Experimental Section) is 22.2% (Mo 2 C-100/Mo 2 N-200) and 1.7% (Mo 2 C-002/Mo 2 N-111), corresponding to semicoherent and coherent interfaces, respectively, conversely confirming the probable elongated N− Mo−C bonds at these interfaces. 24 Functional Characteristics of Asymmetric Chemical Potential Activated Nanointerfacial Electric Fields.…”

“…Of note, the elemental intensity distribution curves (inset in Figure j) along the red dashed line, screening Mo, C, and N, adequately disclose the discrepancy of elemental distribution cross from Mo 2 C to Mo 2 N sublattice body, further implying the presence of the heterogeneous configuration. More essentially, in the case of a thermodynamically governed epitaxial growth process, steady-state interfacial reconstruction (white dotted arrows in Figure j-k) occurs at atomic-scale N–Mo–C binding region, which may endow these interfaces with distinctive electronic properties . Additionally, the calculated lattice mismatch (detailed in the Experimental Section) is 22.2% (Mo 2 C-100/Mo 2 N-200) and 1.7% (Mo 2 C-002/Mo 2 N-111), corresponding to semicoherent and coherent interfaces, respectively, conversely confirming the probable elongated N–Mo–C bonds at these interfaces …”

“…The reason for this lack of efficiency is the low-grade intrinsic catalytic activity at the active sites, where the charge-transfer process and adsorption behavior of active species at the intrinsic activity-dominated region is sluggish (Figure a) and hence unable to cater for fast kinetics. Some emerging strategies, such as electric fields based on semiconductor heterojunctions, can effectively optimize the charge transfer and adsorption processes of reactant species by modulating the coordination and electronic band structures within heterojunctions. − Bearing validations to the point are the recent studies on hydrogen evolution reaction (HER) and CO 2 reduction reaction (CO 2 RR) lying in the heterogeneous interfaces with superior intrinsic activity. , Sun et al developed a FeN/Fe 3 N heterojunction for electrochemical CO 2 RR with a modified interfacial environment for preferential adsorption and reduction of CO 2 , resulting in a dramatically improved catalytic efficiency . However, there remains a gap on the explanation of the chemical and physical origins of redox reactions catalyzed by heterojunction sites in VRFB, let alone unraveling its structure–property-function correlation.…”

Lithium Polysulfide Catalytic Mechanism of AlN/InN Heterojunction by First-Principles Calculation

“…The band gap of AlN/Al 2 O 3 heterojunctions has been reduced significantly, making it about 3.9 eV that is owing to the competition between the elongated Al-N and Al-O bonds across the interface. And the incoherent interface can generate a very strong interfacial ultraviolet light emission [22]. In this paper, we have designed a strong polarization AlN/InN heterojunction and studied its ability in terms of LiPS conversion in Li-S batteries in the following sections.…”

Borrowed dislocations for ductility in ceramics

“…The ELF map illustrates strong electron localization between Mo and O atoms, reaffirming robust Mo-O bonds with a mixed covalent and ionic character. This may substantially contribute to strengthening the interfaces and thereby facilitate our borrowing-dislocations strategy ( 29 , 30 ).…”