Electronic structure of small GaAs clusters

First-principles study on stability and photoelectron spectroscopy of Ga(n)As2(n = 1-9) clusters

The stability and photoelectron spectroscopy of the Ga(n)As2(n=1-9) clusters have been studied by using first-principles based on density functional theory (DFT). Our calculations reveal that the stabilities of the Ga(n)As2(n=1-9) clusters tend to increase with the increase of the number of total atoms. The calculated second-order difference values of the binding energy show a certain law of even-odd alternation, and the value of the even-numbered clusters is much larger than those of the odd-numbered ones. The energy gap Egap also shows a certain law of even-odd alternation, i.e. the Egap of the even-numbered clusters is much larger than the odd-numbered ones. The Egap of the clusters is between 0.2 eV and 0.6 eV, it will provide a reference for GaAs defect level research. The Ga(n)As2(n=1-9) clusters are potential to detect and emit THz radiation due to their ground-state vibration frequency are in THz range.

AB INITIO STUDY OF DIFFERENT PROBABLE STRUCTURES OF GROUP III ANTIMONIDES

Ab initio studies of the small ( AlSb , InSb , GaSb ) clusters is performed to investigate the changes in structural, vibrational and electronic properties. The calculated results clearly demonstrate that any change in the electronic configuration of the neutral clusters gives rise to noticeable changes in the structure. The structures of the neutral, positively and negatively charged clusters are fully optimized, taking the importance of the symmetry into account in all the cases. The changes in vibrational properties are explained keeping in mind the change in the interatomic distances due to any change in the electronic configuration.

Theoretical study of aluminum arsenide clusters: equilibrium geometries and electronic structures of Al(n)As(n) (n=1-4)

The geometry, electronic configurations, harmonic vibrational frequencies and stability of the structural isomers of Al(n)As(n) clusters (n=1-4) have been investigated using density functional theory. For dimers and trimers, the lowest energy structures are planar cumulenic rings (IIs, VIs) with D(nh) symmetry. The caged structure with T(d) symmetry (IXs) lie lowest in energy among the tetramers. The AlAs bond dominates the structures for many isomers so that one preferred dissociation channel is loss of the AlAs monomer. The atomic charges, hybridization and chemical bonding in the different structures are also discussed. Comparisons with valence-isoelectronic Si(2n), Al(n)P(n) and Ga(n)As(n) clusters of same size, the properties of the aluminum arsenide clusters are analogous to those of their corresponding Al(n)P(n), Si(2n) counterparts. The results can explain the modification and refinement of Si phase in AlSi alloy in the molecular level.

Electronic structure and stability of AlnPn (n = 2-4) clusters

The geometry, electronic configurations, harmonic vibrational frequencies, and stability of the structural isomers of aluminum phosphide clusters have been investigated using the density functional theory. For dimers and trimers, the lowest energy structures are cyclic (IIs, IIIs) with D(nh) symmetry. The caged structure with Td symmetry (Xs) lie lowest in energy among the tetramers. The Al--P bond dominates the structures for many isomers so that one preferred dissociation channel is loss of the AlP monomer. The hybridization and chemical bonding in the different structures are also discussed. Comparisons with silicon and boron nitride clusters, the ground state structures of Al(n)P(n) clusters are analogous to those of their corresponding Si(2n) counterparts. This similarity follows the isoelectronic principle.