Abstract: The geometric structures, stabilities, and electronic properties of In_nAs_n tubelike clusters at up to n=90 and single-walled InAs nanotubes (InAsNTs) were studied by density functional theory (DFT) calculations. The lowest-energy structures and electronic properties of the small In_nAs_n (n=1-3) clusters are consistent with those found in earlier studies. A family of stable tubelike structures with In-As alternating arrangement was observed when n≥4 and their structural units (four-membered rings and sixmembered rings) obey the general developing formula. The average binding energies of the clusters show that the tubelike cluster with eight atoms in the cross section is the most stable cluster. The sizedependent properties of the frontier molecular orbital surfaces explain why we can successfully obtain long and stable tubelike clusters. They also illustrate the reason why InAsNTs can be synthesized experimentally. We also found that the single-walled InAsNTs can be prepared by the proper assembly of tubelike clusters to form semiconductors with large bandgap.

Key words: In_nAs_n tubelike cluster, InAs nanotube, Density functional theory, Geometric structure, Stability, Electronic property