First example of lanthanum as dopant on Al12N12 and Al12P12 nanocages for improved electronic and nonlinear optical properties with high stability

The electronic and nonlinear optical (NLO) properties of lanthanum doped Al12N12 and Al12P12 nanocages were investigated. The endohedral and exohedral doping of lanthanum were explored. The stability and structure of doped Al12N12, and Al12P12 nanocages were estimated by calculating interaction energies and geometric parameters. The exohedral doping is more favorable as compared to endohedral doping, which is reflected by the interaction energies. The HOMO-LUMO energy gaps were reduced (0.89 eV) in lanthanum doped Al12N12 and Al12P12 nanocages. The density of state plots strongly support the formation of a new high-energy HOMO level. This new HOMO energy level might be responsible for the reduced HOMO-LUMO energy gap. The natural bond orbital (NBO) charge analysis supports the charge transfer from metal towards the respective nanocage. The first hyperpolarizability was remarkably enhanced as compared to the pristine Al12N12 and Al12P12 nanocages by lanthanum doping. The maximum first hyperpolarizability value (4.43 x 104 au) was obtained for isomer A of Al12N12 series. The present investigation will attract the scientific community in designing the high-performance NLO materials for hi-tech NLO applications.