Fabrication of Micro-Structural ZnO Crystal and the Concentration Fields of the CVD Reactor

Abstract:

Arrayed ZnO crystals were fabricated with Zn as raw material by thermal chemical vapor deposition in a tubular reactor. The characterizations indicate the product grown at upstream is the well-arrayed ZnO submicro-column with good crystal properties, that at downstream is well-arrayed nanoneedle with more defects. In combination of mass field analysis with Fluent, it is revealed that the concentration fields at the upstream and downstream positions of Zn source are not identical even in an identical temperature field. It is the diffusion that drives Zn vapor move to upstream position where the O₂ is rich, and the amount diffuse to upstream is rare due to the transportation of working gas. Most of O₂ is consumed when passes the Zn source, leading to more lean O₂ but rich Zn at the downstream position of Zn source. Our results support that lower concentration of Zn and O₂ is in favor of the formation of perfect crystal as happened at upstream, but in such condition that more Zn and rare O₂, defects of O vacancy is liable to form during ZnO growth.

• Periodical: Advanced Materials Research (Volumes 750-752)
• Pages: 352-357
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.750-752.352
• Online since: August 2013
• Authors: Jun Bo Xu, Hui Juan Tian, Ya Jun Tian, Hao Wen
• Keywords: Computational Fluid Dynamics (CFD), CVD, Flow Field Analysis, ZnO Crystals

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