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Jan Linnros

Publications and source records attributed to Jan Linnros.

4 recordsLinked to original sources
PubMed2005

Fabrication of colloidal crystals with tubular-like packings.

Methods are reported for the fabrication of colloidal crystal wires with tubular packings. Both free and silica-encased wires have been prepared. Porous silicon membranes are infiltrated with silica spheres, treated with silane, and annealed. After removal of the silicon template, short annealing times were found to result in colloidal crystal wires with varied packing geometries, while repeated annealing cycles produced a thin translucent silica sheath around the wires. Packing in the wires varies with the channel diameter of the Si membrane. The channels used in this study typically produce colloidal crystal wires with six strands, though wires with four to seven strands have been observed. Both chiral and achiral packings are also possible.

Biocompatible Materials↗
PubMed2005

Narrow luminescence linewidth of a silicon quantum dot.

Single-dot luminescence spectroscopy was used to study the emission linewidth of individual silicon nanocrystals from low temperatures up to room temperature. The results show a continuous line narrowing towards lower temperatures with a linewidth as sharp as 2 meV at 35 K. This value, clearly below the thermal broadening at this temperature, proves the atomiclike emission from silicon quantum dots subject to quantum confinement. The low temperature measurements further reveal a approximately 6 meV replica, whose origin is discussed. In addition, an approximately 60 meV TO-phonon replica was detected, which is only present in a fraction of the dots.

Journal Article↗
PubMed2005

Controlled fabrication of silicon nanowires by electron beam lithography and electrochemical size reduction.

We demonstrate that electrochemical size reduction can be used for precisely controlled fabrication of silicon nanowires of widths approaching the 10 nm regime. The scheme can, in principle, be applied to wires defined by optical lithography but is here demonstrated for wires of approximately 100-200 nm width, defined by electron beam lithography. As for electrochemical etching of bulk silicon, the etching can be tuned both to the pore formation regime as well as to electropolishing. By in-situ optical and electrical characterization, the process can be halted at a certain nanowire width. Further electrical characterization shows a conductance decreasing faster than dimensional scaling would predict. As an explanation, we propose that charged surface states play a more pronounced role as the nanowire cross-sectional dimensions decrease.

Crystallization↗