Nanowires in the CdHgTe Material System

• Published in: Journal of electronic materials 2008-09, Vol.37 (9), p.1311-1317
• Main Authors: Haakenaasen, R., Selvig, E., Hadzialic, S., Skauli, T., Hansen, V., Tibballs, J.E., Trosdahl-Iversen, L., Steen, H., Foss, S., Taftø, J., Halsall, M., Orr, J.
• Format: Article
• Language: English
• Subjects: Cadmium; Characterization and Evaluation of Materials; Chemistry and Materials Science; Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Electronics and Microelectronics; Exact sciences and technology; Instrumentation; Low-dimensional structures (superlattices, quantum well structures, multilayers): structure, and nonelectronic properties; Materials Science; Mercury cadmium telluride; Methods of deposition of films and coatings; film growth and epitaxy; Methods of nanofabrication; Molecular beam epitaxy; Molecular, atomic, ion, and chemical beam epitaxy; Nanoscale materials and structures: fabrication and characterization; Nanowires; Optical and Electronic Materials; Physics; Quantum wires; Self-assembly; Semiconductor research; Silica; Solid State Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties)
• ISSN: 0361-5235; 1543-186X
• DOI: 10.1007/s11664-008-0414-7

HgTe nanowires have been grown by molecular beam epitaxy (MBE). They are nucleated at Au particles on Si or GaAs substrates and subsequently self-organize and grow laterally on the surface into 20–50 nm wide, 0.5–1  μ m long twisted, but single-crystal, wires. Further growth gives longer, wider, and straighter polycrystalline wires. When unimpeded by Au particles on the surface, the wires become straight and consist of segments of cubic 〈111〉 HgTe and hexagonal 〈001〉 Te parallel to the wire. Te nanowires and Au␣nanowires have also occasionally been formed. All attempts to grow CdHgTe on Si substrates with or without Au particles have resulted in polycrystalline layers. The phase diagrams and diffusion coefficients imply that CdHgTe or HgTe nanowires will not grow by the vapor–liquid–solid technique at the low MBE growth temperatures. SiO 2 functions as a mask for selective growth of HgTe, but not for CdHgTe.