Structural properties investigation of Zinc telluride (ZnTe) nanoclusters doped with aluminum and phosphorus using DFT and GaussView 6

This study investigates the effect of aluminum and phosphorus doping on the structural and electronic properties of zinc telluride (ZnTe) nanoclusters, which are of potential interest for applications in solar cells, photodetectors. The aim is to explore how such doping modulates electronic behavior, chemical reactivity, and optical response. Density Functional Theory (DFT) was employed to investigate the molecular structure, electrostatic potential (ESP), density contour maps, infrared (IR) spectra, point group symmetries, frontier molecular orbital energies (HOMO, LUMO), energy gap (), total energy, dipole moment, polarizability, global electronic properties including ionization potential (I.P), electron affinity (E.A), electronegativity (χ), electrophilicity () and density of states (DOS) using the CAM-B3LYP and LanL2DZ basis sets, via the Gaussian 09 and GaussView 6 software packages. Doping significantly influenced the physical and chemical properties of ZnTe nanoclusters. Doping reduced the ZnTe energy gap from 5.09 eV to 3.5–3.8 eV, indicating a transition from insulating to semiconducting behavior. Total energy values showed a marked increase in stability after doping, with the most stable cluster reaching –20740.45 eV. Dipole moments increased noticeably, ranging from 1.92 D in the undoped system to 10.22 D in the highly doped clusters, indicating stronger charge separation. Similarly, the average polarizability rose from 477.45 a.u. to 1733.4 a.u., confirming increased molecular flexibility and electronic responsiveness. Vibrational spectra revealed new peaks associated with novel bonds such as Zn–Al and Te–P, confirming successful doping. Finally, DOS analyses showed that doping introduced additional energy states that can be occupied by electrons, potentially altering the optoelectronic behavior of the clusters.