Using intruded gold nanoclusters as highly active catalysts to fabricate silicon nanostalactite structures exhibiting excellent light trapping and field emission properties

Abstract

The use of metal catalyst to prepare nanostructures on semiconductor materials has attracted much attention because of the improved device performance. In this study, we employed the intruded Au nanocluster (INC) technique to prepare highly uniform, “atomic-scale” Au nanoclusters as highly active catalysts within Si wafers. The Au nanoclusters were readily prepared through the thermal coating of a Au film on a Si wafer followed by its removal using adhesive tape. Employing the Au nanoclusters as highly active catalysts allowed us to readily and rapidly prepare, at room temperature, unique Si nanostalactite (SNS) structures of ultrahigh density and very narrow diameter (ca. 10 nm). These SNS structures possessed superior light trapping capability relative to corresponding structures prepared using electroless metal deposition or self-assembled catalytic nanoparticle methods; in addition, the etching duration was much shorter. A field emission study revealed that the SNS structures, with their much narrower diameters, required a much lower turn-on voltage relative to that of corresponding Si nanowires.