Fabrication of antireflective silicon nanowires array

In this work, vertical aligned SiNWs array have been fabricated on silicon wafers via metal assisted chemical etching method. This method mainly contains four fabrication steps: wafer cleaning, oxide layer removal, silver catalyst deposition and metal assisted etching. The relationship between the etching time and nanowires length is investigated, and the nanowires can be fabricated in a controllable manner. The optical characteristic of the nanowires array is measured. The average optical reflectance of the SiNWs array is as low as about 3.28% when the etching time is 20 min, implying such prepared SiNWs array possesses an excellent antireflective property. The successful transfer of the SiNWs array from the rigid silicon substrate onto a flexible PDMS film demonstrates its potential in fabricating flexible optoelectronic devices.