Study of Morphological and Related Properties of Aligned Zinc Oxide Nanorods Grown by Vapor Phase Transport on Chemical Bath Deposited Buffer Layers

• Published in: Crystal growth & design Vol. 11; no. 12; pp. 5378 - 5386
• Main Authors: Byrne, Daragh, Fath Allah, Rabie, Ben, Teresa, Gonzalez Robledo, David, Twamley, Brendan, Henry, Martin O, McGlynn, Enda
• Format: Journal Article
• Language: English
• Published: Washington,DC American Chemical Society 07.12.2011
• Subjects: Chemical synthesis methods; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Methods of nanofabrication; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Physics; Quantum wires; Vapor phase epitaxy; growth from vapor phase; Buffer layer; Nucleation; Critical value; Crystal seeds; Crystal growth from vapors; Layer thickness; Silica; Deposition process; Interfaces; Vapor deposition; Transmission electron microscopy; Chemical transport; Vapor phase; Growth mechanism; Zinc oxide; Transport processes; Nanorod; Nanostructured materials; Nanomaterial synthesis
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg200977n

c-axis aligned ZnO nanorods were deposited by vapor phase transport on textured chemical bath deposited buffer layers. In this work, we examine the role of the buffer layer and how it influences the vapor phase transport deposition process using both scanning and transmission electron microscopes and related techniques. Vapor phase transport deposition on chemical bath deposited buffer layers is a complex growth process with many simultaneously occurring effects including (i) substantial morphological transformation at high temperature, which influences the base of the nanorods; (ii) the formation of a mixed amorphous/crystalline Zn x Si1–x O y interface during the vapor phase transport growth on silicon substrates; (iii) the overgrowth of the ZnO seed layers by the silica interface rendering them inactive for nanorod nucleation, suggesting there is a minimum critical thickness ZnO buffer layer necessary for vapor phase transport growth of ZnO nanorods on silicon substrates. We discuss the relative importance of these effects on the overall growth process and use this understanding to explain previous results in the literature.