Microstructured silicon——a new type of opto－electronic material

Arrays of sharp spikes have been formed on the surface of silicon by cumulative femtosecond laser pulse irradiation in an SF6 atmosphere. The absorbance of light by silicon with a microstructured surface is approximately 90% throughout the region from the ultraviolet (250nm) to the near infrared (2500nm). The sharp spikes formed on the surface using femtosecond laser－chemical etching are also good field－emitters. With its amazing optoelectronic properties, surface microstructured silicon shows promising potential applications in the manufacture of solar cells, optoelectronic detectors, flat displays and so forth.