Research on controllable preparation and optical properties of gold catalysed silicon nanowires

Silicon nanowires are the typical representative of new one-dimensional semiconductor nanomaterials. The ultrathin anodic aluminium oxide membrane was employed as the template for reproducing ordered ultrathin gold nanomeshes array. The silicon nanowires arrays with controllable size and shape distribution were prepared by wet etching of monocrystalline silicon under the catalysis of gold film, and their optical properties were studied. The results show that the chemical properties of gold instead of silver as a catalystare more stable than that of silver, which can effectively avoid the secondary etching and overcome the structural damage of silver film at higher temperature or longer etching time, and the silicon nanowires arrays with regular shape and controllable size can be obtained. The reflectivity and transmissivity of the arrays in the band of 400 nm~1200 nm were tested, and the similarities and differences of mechanism between the gold film catalysis and the conventional method were compared. The test results indicate that, compared with conventional metal-assisted chemical etching, the size and distribution of silicon nanowires arrays prepared by the gold film catalytic method proposed are more uniform and controllable, and the anti-reflective properties are effectively improved in broadband spectrum.