Computational Study of Electronic Structure and Transport Properties of PAl₁₂-Based Nanocluster Complexes

Rational design and fabrication of nanoscale devices take the center stage in the current era of information science and technology. In this study, we propose using semiconducting cluster complexes constituted of atomic clusters and choices of ligands as crucial components in electronic devices. The electronic structure and transport properties of PAl₁₂-based nanocluster complexes are investigated by density functional theory (DFT) in combination with the non-equilibrium Green’s function (NEGF) method. Joining two PAl₁₂ clusters via a germanium linker creates a stable semiconducting complex with a large HOMO−LUMO gap. Sequential attachment of an electron-donating ligand, N-ethyl-2-pyrrolidone, to one of the two linked clusters results in the shifting of the electronic spectrum of the ligated cluster while the energy levels of the unligated cluster are mostly unchanged. As a result, the transport properties of the complex are highly dependent on the number of attached ligands. This dependence is discussed in light of the nature and location of molecular orbitals, the coupling to the electrodes, and the delocalization of the resultant transmission orbitals.