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Supercritical chemical fluid deposition (SCFD) from [ n Bu 2 In( μ-E t Bu 2 ) 2 In n Bu 2 ] precursors (E = P or As) dissolved in a homogeneous hexane/CO 2 fluid results in the growth of a thin film of InP or InAs with a thick mat of nanowires attached to the surface. InP films were well-adhered to the substrate and the nanowires can be removed without disrupting the film; however, the InAs films were poorly adhered, being dislodged simply by tapping the substrate. In many cases, the InP nanowires are single crystalline, and both the nanowires and the underlying films exhibit band-edge luminescence. Use of supercritical CHF 3 as the delivery solvent also leads to good quality InP films and reduced carbon incorporation into the films. The single-source precursor system was responsible for significant amounts of carbon. This work shows that the SCFD method may be generally applicable to the growth of compound semiconductors, with important implications for growth of these materials in confined environments.

The main advantage of deposition from supercritical fluids over conventional CVD is the ability to fill high aspect ratio templates. Deposition of metals, indirect semiconductors and insulators into templates with dimensions down to 3 nm has been demonstrated by others, with no apparent pore blocking. In this paper we present a demonstration that it is also possible to deposit high quality, luminescent compound semiconductor films from supercritical CO 2 or CO 2 /hexane mixtures. Depositions of CdS and III-V materials such as InP have been achieved through careful optimisation of precursor chemistry, reactor geometry and deposition conditions, supported by detailed measurements of the semiconductor film properties.