lanthanum nitride (LaN) is an important semiconductor for a variety of applications. It is used as a precursor in the production of phosphors, as a host material in fluorescent lighting and X-ray detectors, and for petroleum cracking catalysts. It is also an ingredient in hydrogen-storage alloys and rechargeable batteries.
Structural and Electronic Properties of LaN with HSE and Spin-Orbit Coupling
The bandgap of LaN is 0.62 eV at the X point, with a direct gap at X that extends up to the p3-p1/2 bands. The valence band is mainly derived from N 2p orbitals, while the conduction band is mainly based on spatially extended unoccupied La 5d orbitals.
Compared with other III-nitrides, LaN has a band alignment similar to ScN and has a relative band offset of 0.3 eV at the interface. This offset is comparable to the
Although lanthanum nitrides enable highly efficient ammonia synthesis, they are prone to chemical sensitivity to air and moisture. We demonstrate that by introducing Al into the LaN lattice, a metallic bond can be formed between the lattice N and the surface, resulting in improved durability under air and moisture without altering the catalytic functionalities. Moreover, the effect of the metallic bond formation on the catalytic activity is comparable to previously reported TM/LaN catalysts, suggesting that La-Al metallic bonds can be an effective mechanism for improving the chemical stability of rare-earth nitrides with retention of their catalytic functionalities.