Enhancing the Electronic and Optical Properties of Germanium Nanoclusters through Alkali Metal Doping: A Case Study on Na₂

Abstract

Abstract In the present study, we have examined the key insight into structural, electronic, and optical properties of Na2 doped germanium nano-cluster using density functional theory. Analysis of binding energy (BE) indicates enhanced thermodynamical stability increases with cluster size, where Ge5Na2 and Ge10Na2 exhibiting highest BE. Second order energy suggest that cluster with n = 2, 5, 6, and 9 are most stable while thpse with n = 3, 4, and 7 shows lower stability. Embedding energy (EE) shows decreases curve with cluster size indicating large clusters are more favourable for Na encapsulation. Large HOMO-LUMO gap ranges from 1.4 to 3.2eV illustrate semiconductor nature of clusters. Further investigation of hyperpolarizability suggesting non-linear optical (NLO) activity for GenNa2 (n = 1-4), while lower NLO features shown in high symmetry clusters with n = 5 and 6. These results imply that GenNa2 clusters have potential uses in optoelectronic and semiconductor devices.