A density functional study on geometries, electronic and photo sensitized surface properties of the fullerene-like BGe nanomaterials

• Published in: Journal of alloys and compounds 2020-03, Vol.817, p.152686, Article 152686
• Main Authors: Zhao, Run-Ning, Chen, Rui, Han, Ju-Guang
• Format: Article
• Language: English
• Subjects: Absorption spectra; Boron; Cages; Charge transfer; Density functional theory; Density of states; Electronic properties; Energy absorption; Energy gap; Fullerenes; GeB nanomaterials; Germanium; Infrared spectra; Inner hollow cages; Mathematical analysis; Molecular orbitals; Nanomaterials; Quantum confinement; Relative stability; Solar energy conversion; Solar energy conversion and absorption; Surface; Surface properties
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.152686

Geometries associated with relative stabilities, infrared spectra, and energy gaps of the slightly deformed (Ge6B6)n (n = 2–10) nanocages are systematically investigated applying density functional theory. Particularly, the relative stabilities in terms of the calculated averaged atomic binding energies and fragmentation energies show that (GeB)36 cage has enhanced stability over other nanoclusters. Interestingly, (Ge6B6)n nanocages prefer to the sphere-like geometries with large inner hollow spaces. Moreover, the calculated energy gaps of (Ge6B6)n nanocages are decreased generally and the wavelengths of absorption spectra in sphere-like (Ge6B6)n clusters are elongated with the increased size of (Ge6B6)n nanocages. The quantum confinement effect indirectly is revealed; furthermore, the nanosized (GeB)36-60 cages have a very stronger capacity for solar energy absorption or conversion due to narrow energy gaps and large DOS near LUMO and HOMO levels. Additionally, germanium atoms transfer electronic charges to their surrounding boron atoms, charge-transfers between Ge and B enhance stabilities of the nanocages. SH2 gas is sensitive to GeB cage and can be used to removal SH2 from air. Nanoclusters exhibit unique geometrical and electronic properties in that they do not present bulk-like core regions due to the strong influence of the higher number of surface atoms and corresponding electronic effects. Since the physical, chemical, optical, magnetic, and electronic properties of nanoclusters are found to vary remarkably with their sizes and compositions. The development of materials composed of boron-germanium matrices are an important area within the semiconductor technology field, which can be applied in the construction of high performance bipolar transistor devices. [Display omitted] •The charge-transfers and surface stabilities of (Ge6B6)n nanocages are increased at larger size cage.•Energy conversion and wavelength of absorbtion spectra for (Ge6B6)n nanocages are increased with size being extended.•Quantum confinement effect and metallic characters in (Ge6B6)n are revealed.•The (Ge6B6)n at large-size tend to be ionic semiconductor materials.