Structural, electronic, magnetic, and optical properties of exfoliated chromium nitride ultrathin films

Ultrathin films of chromium nitride have been studied by density functional theory and their structural, magnetic, and optical properties have been investigated using the first-principles approach. The films are constructed by stacking monolayers of CrN one by one. Accordingly, three models of thin films composed of four, six, and eight layers have been designed. The constructed thin films demonstrated the lowest energy when the interlayer separation is set to 2.35 Å. Our results for the electronic structures indicated that these thin films are having metallic behavior, which is primarily contributed by the Cr-d and N-p states dispersed over the Fermi level. The electronic structures determined for the up and down spin channels demonstrated a high degree of anisotropy which has induced spontaneous magnetic moment. The magnetic moment per formula unit is observed to be increasing with increasing the layer thickness. In addition, these thin films show interesting optical properties including high optical absorption, which can potentially be used for optoelectronic applications.