Investigation of structural, IR spectral, thermodynamics and excitation property alterations in (AlN)12 cluster under external electric fields

Abstract

In recent years, there has been a growing global interest in ultra-wide bandgap semiconductor materials, with aluminium nitride emerging as a particularly promising material. Using density-functional theory (DFT) at the CAM-B3LYP/6-311G(3d,2p) basis set level, we have systematically optimized the geometries of the (AlN)₁₂ cluster. Furthermore, the structural and thermodynamic changes of these clusters under the external electric field (EEF) were investigated. When the external electric field intensity increased the energy gap decreases continuously, infrared spectral analysis showed an obvious Stark effect, and the molecular structure showed significant alterations. Additionally, the study examined orbital compositions and excitation properties of twenty excited states using time-dependent density-functional theory (TD-DFT). The results indicated a decrease in excitation energy with increasing EEF, resulting in longer wavelengths and red-shifted spectral. These findings provide an opportunity to precisely modulate the electronic properties of (AlN)₁₂ cluster by controlling the strength and direction of the EEF, opening up more possibilities for their application in photoelectronic devices.

Graphical abstract