Theoretical analysis of the radius of semiconductor nanowires grown by the catalytic vapour–liquid–solid mechanism

• Published in: Journal of physics. Condensed matter 2006-04, Vol.18 (15), p.3875-3885
• Main Authors: Joon Kwon, S, Park, Jae-Gwan
• Format: Article
• Language: English
• Subjects: Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Materials science; Nanoscale materials and structures: fabrication and characterization; Other topics in nanoscale materials and structures; Physics
• ISSN: 0953-8984; 1361-648X
• DOI: 10.1088/0953-8984/18/15/029

We present a theoretical analysis of the radius, rC*, of semiconductor nanowires (SNWs) grown by the catalytic vapour-liquid-solid (VLS) mechanism. Two types of the catalytic metal were examined, namely case I: thin film, and case II: colloids or cluster. In case I, the number density along with the inter-distance between two neighbouring nucleus, D, and the critical radius of the catalytic metal nucleus, RC*, were correlated and determined by either the thermodynamic relationship (determination of RC* followed by D) or structural instability (determination of D followed by RC*). In case II, the linearly scaling behaviour of rC* with the observed radius of the SNWs was explained by comparing with experimental data obtained from the literature. Commonly in both cases, it was shown that rC* is thermodynamically determined, assuming the kinetic effect due to the initial diffusion length of the gaseous semiconductor precursor in the early stages of the growth of the SNWs, and that rC* mirrors RC* only when rC* is greater than RC*. We also found that the theoretical analysis of rC* is matched well with experimental data in the literature.