Experimental and theoretical investigation on binary semiconductor clusters of B/Si and Al/Si

Abstract

ASi S n (A ¼ B and Al; n ¼ 1-6) binary cluster anions were generated by laser ablation of samples composed of mixtures of Si and A (A ¼ B and Al), and studied in the gas phase by tandem time-of-flight mass spectrometry. Some abundant ions are present in the mass spectrum, indicating that the clusters with these ions have stable structures. The structures of ASi S n clusters were investigated theoretically by the density functional theory (DFT) method and the energetically lowest-lying structures were obtained. The binary clusters BSi S n and AlSi S n , with the same number of n, share different geometric structures except for ASi S n with n ¼ 1 and 6, which have the same geometric structures in the ground state. For all the anionic clusters ASi S n , the lower spin state is lower in energy than the higher spin state in their optimized structures except for the linear ASi S anions, for which the triplet state is lower in energy than the singlet. Calculations of the bonding energy (BE), energy gain (D) and HOMO-LUMO energy gaps confirm that the cluster ASi S 5 has a very stable structure, which agrees well with the experimental results.

Structural evolution and bonding properties of BSin−/ (n = 4–12) clusters: Size-selected anion photoelectron spectroscopy and theoretical calculations

“…For the BSi 4 − cluster, the most stable isomer (4A) can be viewed as a distorted bowl-shaped BSi 4 structure with C 2v symmetry, which is similar with the lowest-lying isomers of BSi 4 −/0 reported in the literature. 24,28,32 Isomer 4B is a C 3v symmetric trigonal bipyramidal structure with the B atom at the apex position and is slightly higher in energy than isomer 4A by 0.11 eV. The theoretical VDE of isomer 4A (2.74 eV) is in reasonable agreement with the experimental peak at 2.92 eV and that of isomer 4B (3.26 eV) is consistent with the experimental peak at 3.30 eV.…”

“…The most stable isomer (6A) of BSi 6 − can be described as a Si atom hanging over a distorted bowl-shaped BSi 5 framework with C 5v symmetry, similar with the lowestlying isomers of BSi 6 −/0 reported in the literature. 24,28,30,32 The theoretical VDE of isomer 6A (3.51 eV) is in reasonable agreement with the experimental value (3.61 eV), and its DOS spectrum can reproduce the peak positions and patterns of the experimental spectrum very well. The existence of isomers 6B, 6C, and 6D can be ruled out because they are much higher in energy than isomer 6A by at least 1.05 eV.…”

“…22 The growth mechanisms of small BSi n clusters were investigated by time-of-flight mass spectrometry and theoretical calculations. [23][24][25][26] Quantum chemical calculations predicted that BSi 8 + has a stable cubic structure with the B atom a) Authors to whom correspondence should be addressed: xlxu@iccas.ac.cn;…”

Characterization of neutral boron-silicon clusters using infrared spectroscopy: The case of Si6B

“…Density functional theory (DFT) calculations for SiB2, Si2B, and Si2B2 found stable ring-like structures with strong -bonding [23]. Anionic SinB -clusters (n=1-6) formed by direct laser ablation from a mixed B/Si sample were studied by mass spectrometry and DFT calculations [24]. In that work, Si6B -was predicted to have C5v symmetry ( 1 A1), whereas its neutral counterpart was suggested to have Cs symmetric geometry ( 2 A') [25].…”

Structure, stability, absorption spectra and aromaticity of the singly and doubly silicon doped aluminum clusters AlnSim0/+ with n = 3–16 and m = 1, 2

“…Earlier studies mainly examined the Al doped Si clusters. [50][51][52] whereas only a few studies on the Si doped Al clusters were performed and concentrated on high symmetry structures 53,54 that are not necessarily the most thermodynamically stable structural motifs.…”