Integrated silicon nanowire diodes and the effects of gold doping from the growth catalyst

Abstract

We report on integrated, silicon single-nanowire diodes. Gold catalyst templates, defined by lithography, controlled the location of nanowires grown with a vapor-liquid-solid mechanism. The nanowire growth, by atmospheric-pressure chemical vapor deposition, used SiCl4 diluted in H2 on (100) n-type silicon substrates. Postgrowth oxidation and wet etching reduced the nanowire diameters and removed unintentional small diameter nanowires. Spin-on glass isolated the nanowire tips from the substrate, which were then contacted with aluminum. Current-voltage measurements show rectification and ideality factors consistent with pn junction diodes. However, the gold catalyzed nanowires have much higher than expected hole concentrations that cannot be explained by behaviors reported for gold diffused into silicon.

GaAs nanopillar-array solar cells employing in situ surface passivation

“…These values can be attributed to several factors. First, the SAE approach does not require any catalyst34 (for example, gold or copper) to initiate the growth, avoiding any metal incorporation within the GaAs crystal that has been reported to increase the reverse bias leakage current in nanowire-based devices45. Second, the high-bandgap InGaP shell minimizes the surface state density on the nanofacets that could partly deplete the inner n–p core–shell junction.…”

Interface pn junction arrays with high yielded grown p-Si microneedles by vapor–liquid–solid method at low temperature

“…That is, doping of VLS grown Si needles was demanded. In literature we find several reports [7,8] on VLS grown doped Si nanowires, having diameter in nanometer range, and their devices. However, considering our target applications (e.g.…”

Titanium catalyzed silicon nanowires and nanoplatelets

“…Silicon nanowires have most typically been grown using gold droplets to catalyze growth at the nanowire end facet via the vapor liquid-solid (VLS) mechanism, 1, 2 though a number of other catalysts have been studied, 3,4 in part to avoid the problems of the midgap states from the fast-diffusing gold impurity in silicon. 5 Titanium, deposited in thin layers and annealed to form titanium silicide islands, can catalyze silicon nanowires with a vapor-solid-solid (VSS) mechanism. [6][7][8][9] The VLS and VSS mechanisms favor the anisotropic one-dimensional morphology in cubic covalent materials such as silicon, 2 though branching networks of silicon nanowires forming on other nanowires have been reported.…”