Size-induced structural transition in ZnO prismatic nanoparticles

✍ Scribed by Vu Ngoc Tuoc; Tran Doan Huan

• Book ID: 104542025
• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 979 KB
• Volume: 249
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/pssb.201147356

✦ Synopsis

Abstract

We report a first‐principles study on several series of zinc oxide prismatic nanoparticles (NPs) with triangular and hexagonal cross‐section geometries and various diameters up to 2.4 nm. Structural and electronic properties of the NPs are calculated using density functional theory, focusing on the effects induced by the surfaces reconstruction and the quantum sizes of the structures. We have observed a transition from the rocksalt structure for short NPs to the wurtzite structure for long NPs. These two structures are found to correspond to two mechanisms of surface stabilization, which are also observed in short and long NPs. For short NPs, the surfaces are stabilized by merging two polar facets of each layer into one while for long NPs, an “effective charge transfer” between two outer base surfaces is the key mechanism for surface stabilization. Effects of sizes and surfaces on electronic properties of the structures, e.g., the highest occupied molecular orbital (HOMO)–lowest unoccupied molecular orbital (LUMO) gap, are examined to support the discussion of the structural transition and the polar surface stability.