Ultrafast laser microtexturing of silicon for optoelectronic devices

Presentation Date: 

Thursday, January 24, 2002


Photonics West: Commercial and Biomedical Applications of Ultrafast Lasers (San Jose, CA)

Presentation Slides: 

Arrays of sharp, conical microstructures are obtained by texturing the surface of a silicon wafer using femtosecond laser-assisted chemical etching. The one step, maskless texturing process drastically changes the optical and electronic properties of the original silicon wafer. These properties make the textured silicon viable for use in a wide range of commercial devices. Near-unity absorption of light, from visible to infrared wavelengths, offer opportunities for use in optically active devices such as solar cells and detectors. Significant enhancement of below-band-gap photocurrent generation in textured avalanche photodiodes shows strong promise for use in infrared photodetectors. Remarkable field emission characteristics indicate great potential in the burgeoning industry of field emission devices. The low turn-on fields and high current yields make the textured silicon ideal for use in field emission displays, ion thruster propulsion, and microwave amplification. The use of silicon is particularly interesting in commercial application due to the low cost and prevalence of silicon in electronics.