Study on the Structure and Property of the Neutral Ga xP y ( x+ y=8) and Anionic Gallium Phosphide Clusters Using DFT

Abstract

Structure, electronic state, and energy of semiconductor binary micro-clusters, Ga x P y and Ga x P y −, having eight atoms have been computed using density functional theory (DFT) method. Structural optimization and frequency analysis are performed at the B3LYP/6-311+G(2 df) level. The charge-induced structural changes of these anions have been discussed. The strong Ga-P bond is favored over the P-P bond in Ga x P y − ( x+ y=8), in comparison with the corresponding neutral cluster. The calculations predict the existence of previously unknown isomers (i.e. Ga 1P 7 −, Ga 2P 6 −, Ga 3P 5 −, Ga 6P 2 −, and Ga 7P 1 −). Among different Ga x P y and Ga x P y − ( x+ y=8) clusters, Ga 4P 4 and Ga 4P 4 − are more stable. Two types of energy separations are reported in this study, adiabatic electron affinities (Δ E AEA) and vertical detachment energies (Δ E VDE), wherever applicable, and are compared with those described in other published data in the literature. Adiabatic electron affinities for Ga 4P 4 and Ga 5P 3 are in good agreement with those obtained in the experiments. Mulliken population analyses indicate that the bonding in GaP clusters is of a mixed type.