Study of the Effect of Selenium Doping on the Geometries and Electronic Characteristics of Germanium Clusters (SeGen, n = 1-20) Using DFT Calculations

Authors I. Zitouni, K.E. Aiadi, O. Bentouila, M. Benaida, Z. Ayat

Laboratory of New and Renewable Energy in Arid and Saharan Zones – LENREZA, Ouargla University, 30000 Ouargla, Algeria

Issue Volume 13, Year 2021, Number 2
Dates Received 05 March 2021; revised manuscript received 15 April 2021; published online 20 April 2021
Citation I. Zitouni, K.E. Aiadi, J. Nano- Electron. Phys. 13 No 2, 02027 (2021)
PACS Number(s) 36.40.Mr, 61.46.Bc
Keywords Selenium-doped germanium clusters, DFT calculations, Stability (15) , Geometry (2) , Electronic properties (3) .

A theoretical systematic investigation based on the calculating geometrical structures, stability, and electronic characteristics of the system (SeGen clusters, n = 1-20) was presented within the framework of density-functional theory (DFT) as implemented in the SIESTA simulation code. All the ground-state isomers obtained have 3D structures. Big SeGen clusters of size n ≥ 16 exhibit higher binding energy. Like-wise, the obtained second-order energy difference Δ2E results show that the positive maximum peaks at n = 2, 4, 8, 11, 14, 17, and 19 have private stability. This signifies that they have a greater stability character than their neighbors. The results of calculations of electronic properties such as highest occupied molecular orbital-lowest unoccupied molecular orbital (HOMO-LUMO) gap, vertical ionization potential (VIP) and vertical electron affinity (VEA) reveal that the SeGe1 dimer is more stable than neighboring clusters. On the other hand, according to the HOMO-LUMO gaps analysis, we conclude that the SeGe2, 4, 6, 9, 11, 13, 17 clusters have lower HOMO-LUMO gap values than the corresponding pure germanium clusters, suggesting that the substitution of one Ge atom by a Se one enhances the chemical reactivity of the host germanium clusters, and thus increases the metallic character of relevant clusters. The results of this study are very important as they open us with good perspectives for the use of these candidate clusters in applications of nanotechnology and nanoelectronics.

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