Observation of vacancy ordering structure in GaP nanobelts

Abstract

III–V semiconductor GaP nanobelts were synthesized with a Fe2O3 catalyst on Si substrates by thermal evaporation at high temperatures. These nanobelts, typically, have a width from 50 to 600 nm and a length of up to several hundred micrometers. Their thickness varies from 10 to 40 nm. A vacancy ordering structure was observed near the edge of the GaP nanobelts. The vacancy ordering structure was analyzed using high-resolution transmission electron microscopy, electron diffraction patterns, and computer simulation. The unit cell of the vacancy ordering structure in the GaP belt is orthorhombic with lattice parameters a=3.767 Å, b=6.525 Å, c=18.456 Å, and α=β=γ=90°. In the [111] projection, the structure is a

R 3 x 3 120° superstructure, while in the [211] projection, it exhibits a superstructure in both the (1¯1¯3) and (1¯31¯) planes. This defective structure can also be visualized as a long period structure with a superstructure in the (111) stacking plane. © 2004 American Institute of Physics.